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AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 5 Coordination.

AP State Syllabus SSC 10th Class Biology Important Questions 5th Lesson Coordination

10th Class Biology 5th Lesson Coordination 1 Mark Important Questions and Answers

Question 1.
“Plants respond to stimuli.” During a project work on it, from which plants do you collect information and record it?
Answer:
a) Mimosa Pudica (Touch me not plant) b) Sunflower c) Cucumber d) Bittergourd

Question 2.
Write two points about insulin from the information you collected from internet. (OR)
Write two sentences about insulin hormone using the data collected from your school library.
Answer:

1. Insulin is secreted by islets of longerhans of pancreas gland.
2. Deficiency of insulin results in diabetis mellitus.

Question 3.
You have performed the activity of Seed Germination in a glass jar in your school lab. You might have observed the growth of shoot and root. What information did you record regarding the shoot growth after a week if the glass jar is tilted and plant kept horizontally.
Answer:

1. More auxins collects on light falling side of the stem.
2. Cells on that side grow faster and make the stem bends towards light due to phototropism.

Question 4.
Write the functions of Spinal-cord from the information collected from your school library and from internet.
Answer:

1. Carries the information to the brain from the lower parts of the body.
2. It carries the information from brain to body parts.
3. It plays a key role in the reflex actions.
4. It acts as relay centre.

Question 5.
Where do we find Cerebro-spinal fluid? Mention one of its functions.
Answer:
The space between the inner layers of brain is filled with fluid called cerebrospinal fluid (CSF). It serves as a shock-absorbing medium and protects the brain against shocks, jerks along with the meninges and cranium.

Question 6.
Mention at least one activity done at school to show involuntary reflexes.
Answer:
Knee-jerk.

Question 7.
Write the name of the nerve given in the following diagram and write its function.
Answer:
The given diagram is the sensory Neuron. They are also called Afferent nerves.
Function: They carry messages towards central nervous system (Brain or spinal cord) from nerve endings on the muscles of different sense organs, that sense the change in surroundings.

Question 8.
Identify the given part in the diagram and write its use.
Answer:
i) Synapse.
ii) It is a functional region of contact between two neurons where infromation from one neuron is transmitted to another neuron.

Question 9.
Name the part of the brain that maintains the equilibrium.
Answer:
The part of the brain that maintains the equilibrium is cerebellum.

Question 10.
Who discovered the first plant hormone auxin?
Answer:
The first plant hormone auxin was discovered by F.W. Went.

Question 11.
What was the belief of Greeks?
Answer:
The Greeks believed that all functions of the body were controlled by the brain, since damage to that organ produced remarkable changes in behaviour.

Question 12.
How many types of nerves are present in human body? What are they?
Answer:
Nerves are classified mainly into three types.

1. Afferent neurons
2. Efferent neurons
3. Association neurons.

Question 13.
What are Afferent neurons?
Answer:
Afferent neurons: Nerves which carry messages towards the central nervous system (Spinal cord or brain) from sense organs are called afferent neurons. These are also called sensory nerves.

Question 14.
What are efferent neurons or nerves?
Answer:
Efferent neurons: Nerves which carry messages from the central nervous system to parts that shall carry out the response are called efferent neurons. They are also called as motor nerves.

Question 15.
What are association nerves?
Answer:
The nerves, which link together the afferent and efferent nerves are called association nerves.

Question 16.
What is stimulus?
Answer:
Stimulus is a thing or event that causes a specific functional reaction in an organ or tissue.

Question 17.
What is response?
Answer:
Response is a effect of a change in the environment of the organism or signals of change or stimuli.

Question 18.
What does rapidity of response indicate?
Answer:
Rapidity of response indicates an efficient communication system linking those parts that pick up stimuli to those that trigger a response.

Question 19.
How are responses bring about?
Answer:
Responses are brought about by rapid changes in some muscle.

Question 20.
According to Galen a Greek physiologist how many kinds of nerves are present in body?
Answer:
According to Galen, nerves are of two kinds. They are 1) for sensation and 2) for action.

Question 21.
What are the major parts of neuron?
Answer:
The major parts of neuron are cell body or cyton, dendrites and axon.

Question 22.
What are the two types of projections that extend from cell body?
Answer:
The two types of projections that extend from cell body are dendrites and axon.

Question 23.
What is synapse?
Answer:
Synapse is the functional region of contact between two neurons.

Question 24.
Synapses are mainly found in?
Answer:
Synapses are mainly found in the brain, spinal cord and around the spinal cord.

Question 25.
What are reflexes?
Answer:
The responses to a stimulus on which we do not have control are called reflexes or reflex action.

Question 26.
What is the importance of reflex action?
Answer:
Reflex action save us from painful or dangerous stimuli.

Question 27.
How many types does the nervous system is divided?
Answer:
Nervous system is divided into two types. They are central nervous system and peripheral nervous system.

Question 28.
What are the parts of central nervous system?
Answer:
The parts of the central nervous system are brain and spinal cord.

Question 29.
What are the three major divisions in brain?
Answer:

1. Forebrain
2. Mid brain and
3. Hind brain.

Question 30.
What are the parts present in fore brain?
Answer:
The parts present in fore brain are cerebrum and diencephalon.

Question 31.
What are cranial nerves? How many cranial nerves are present?
Answer:
Nerves originate from brain are called cranial nerves. 12 pairs of cranial nerves arise from brain.

Question 32.
How many pairs of spinal nerves are present?
Answer:
31 pairs of spinal nerves are present.

Question 33.
Which is called peripheral nervous system?
Answer:
Peripheral nervous system consists of nerves arising from the brain and spinal cord. 12 pairs of cranial nerves from brain and 31 pairs of spiral nerves from spinal card together called peripheral nervous system.

Question 34.
What is autonomous nervous system?
Answer:
The peripheral nervous system that controls the involuntary actions of the body is called autonomous nervous system.

Question 35.
What are the systems involved in control and coordination in animals?
Answer:
The systems involved in control and coordination in animals are nervous system and endocrine system.

Question 36.
The hormone insulin is secreted by?
Answer:
The hormone insulin is secreted by Islets of Langerhans of pancreas gland.

Question 37.
Give examples for endocrine glands.
Answer:
The examples for endocrine glands are pituitary gland, thyroid gland, parathyroid, adrenal, hypothalamus, pancreas, thymus, testes and ovaries.

Question 38.
The nervous system that regulates heart beat, breathing, etc., is?
Answer:
The nervous system that regulates heart beat, breathing etc., is autonomous nervous system.

Question 39.
What is thigmotropism?
Answer:
The directional growth movement of a plant part in response to the touch of an object is called thigmotropism.

Question 40.
Name the receptors of taste and smell.
Answer:
The receptor of taste is gustatory receptor and that of smell is olfactory receptor.

Question 41.
What is reflex action? Give examples.
Answer:
Reflex action is a quick involuntary response to a stimulus by an effector.
e.g: Withdrawing our hand from hot object, blinking of eyelids when a moving object approaches eye.

Question 42.
What is the difference between a reflex action and walking?
Answer:
Reflex action is an involuntary action whereas walking is a voluntary action.

Question 43.
Which part of the brain maintains posture and equilibrium of the body?
Answer:
The part of the brain that maintains posture and equilibrium of the body is cerebellum.

Question 44.
How do we detect the smell of agarbathi or incense stick?
Answer:
We detect the smell of agarbathi or incense stick when the olfactory receptors in the nose detect smell by sending nerve impulses to the olfactory centre of the brain.

Question 45.
What is target tissue?
Answer:
Tissues or organs on which hormones act are called target tissues or organs.

Question 46.
What are the main cells of the nervous system?
Answer:
The main cells of the nervous system are the neurons. Besides the neurons the nervous system also consists of glial cells.

Question 47.
What is phototropism?
Answer:
The movement of a plant part in response to light is called phototropism.

Question 48.
What is geotropism?
Answer:
The movement of a plant part in response to gravity is called geotropism.

Question 49.
What is chemotropism?
Answer:
The movement of a plant part in response to chemical stimulus is called chemotropism.

Question 50.
What is hydrotropism?
Answer:
The movement of a plant part in response to water is called hydrotropism.

Question 51.
How many nerve cells does human nervous system consist of?
Answer:
Human nervous system consists of about 100 billion cells.

Question 52.
What is reflex arc?
Answer:
The structural and functional unit that carries reflex action is called reflex arc.

Question 53.
The three layers covering the brain are called?
Answer:
The three layers covering the brain are meninges.

Question 54.
What are the functions carried out by cerebrum?
Answer:
Cerebrum is a seat of mental abilities, controls thinking, memory, reasoning, perception, emotions and speech.

Question 55.
What are the functions of cerebellum?
Answer:
Cerebellum maintains posture, equilibrium and muscle tone.

Question 56.
Which parts are present in hind brain?
Answer:
Cerebellum and medulla oblongata are the parts present in hind brain.

Question 57.
What is the function of feedback mechanism?
Answer:
The function of feed back mechanism is to regulate the production and release of hormones in the body.

Question 58.
Thyroxine hormone controls the body’s function like?
Answer:
Thyroxine hormone controls body’s function like general growth rate and a metabolic activity.

Question 59.
What are voluntary actions? Give examples.
Answer:
The movements under the control of the conscious mind are called voluntary actions. Example : Kicking foot ball, lifting bucket of water, reading book, running, walking, playing, eating, etc.

Question 60.
What are involuntary actions? Give examples.
Answer:
The movements which are not under the control of the conscious mind are called involuntary actions. Example : Respiration, circulation, digestion.

Question 61.
What is nerve impulse?
Answer:
The information passing through a neuron in the form of electrical and chemical signals is called nerve impulse.

Question 62.
What are phytohormones?
Answer:
The hormones present in the plants are called phytohormones.

Question 63.
The phytohormone Abscisic acid is responsible for?
Answer:
Closing of stomata and seed dormancy are caused by the phytohormone Abscisicacid.

Question 64.
What are the functions of auxins?
Answer:
Auxins are responsible for cell elongation and differentiation of shoots and roots.

Question 65.
What is the speed of nerve transmission?
Answer:
Nerve transmission from stimulus to a response can occur at a maximum speed of about 100 meters per second.

Question 66.
What is vasomotor?
Answer:
Vasomotor refers to actions upon a blood vessel which alter its diameter.

Question 67.
What are dorsal and ventral root ganglion?
Answer:
The dorsal root and ventral root ganglions are the regions very close to the spinal cord in which the nerve cell bodies lie. Dorsal root ganglion is present on the dorsal side of spinal cord and ventral root ganglion is present on the ventral side of the spinalcord.

Question 68.
What is the function of dorsal root ganglion?
Answer:
The dorsal root ganglion carries messages of sensation toward brain or spinal cord.

Question 69.
What is the function of ventral root ganglion?
Answer:
The ventral root ganglion carry the instructions from the brain or spinal card to muscles.

10th Class Biology 5th Lesson Coordination 2 Marks Important Questions and Answers

Question 1.
What questions will you ask a doctor to know about endocrine glands?
Answer:

1. Which glands are known as endocrine glands?
2. Where can we find endocrine glands in our body?
3. What do you call chemical substances secreted by Endocrine glands?
4. Which endocrine gland is attached to the brain?
5. What are the functions of endrocrine glands?
6. What will happen if endocrine glands are absent?

Question 2.
How do you feel when you realize that plants respond to the stimuli of their surroundings?
Answer:

1. It is very interesting and amazing to observe trophic and nastic movements of plants in our surroundings.
2. For example, the bending of shoots of creepers towards light kept near the window.
3. The plant roots always grow downwards.
4. The creepers like cucumber and bittergourds develops tendrils in response to contact or touch.
5. Butterflies fluttering around the flowers for nectar.

Question 3.
What will happen if a plant is placed near the window of your classroom? What is this process called?
Answer:

1. The plant bends towards the sun light and grow.
2. This process is called phototropism.

Question 4.
How do you appreciate the role of Spinal-cord in reflex actions?
Answer:

1. Spinal cord responds very fast and immediate.
2. The nerve impulses are transmitted very fast at the speed of 100 m/min.
3. So that we are protected from many dangerous situations.
4. So I really appreciate and amazing reflex actions of the spinal cord.

Question 5.
Read the following table:

Name of the Gland	Location	Hormone secreted	Function
Thyroid	Neck	Thyroxine	General growth rate and Metabolic activity
Ovary	Abdomen	Estrogen	Growth of uterus and Control of menstrual cycle
Testis	Scrotal sac	Testosterone	Growth of beard, mustache and development of male sex organs.
Adrenal	Kidney	Adrenalin	Increase in heart beat, rise in blood sugar.

Answer the following questions:
i) Which hormone is released at the time of emotions?
Answer:
Adrenaline

ii) Name the hormone responsible for the development of Secondary sexual characters.
Answer:
Estrogen, Testosteron.

Question 6.
Ram met with an accident. After that he lost the capacity to walk in straight manner and cannot smell anything. Which part of the brain got damaged in the above cases?
Answer:

1. The forebrain and hind brain of Ram might have been damaged.
2. The olfactory lobes of the forebrain are concerned with sense of smell. Here, Ram lost the sense of smell anything. Hence the olfactory lobes of forebrain got damaged.
3. The cerebellum of hind brain maintains posture, equilibrium and muscle tone.
4. After accident, Ram lost the capacity to walk in a straight manner and hence, I predict that cerebellum of Ram also got damaged.

Question 7.
What questions will you ask a doctor to know about pancreatic gland?
Answer:

1. Where is pancreas located?
2. Why is it called a mixed gland?
3. What is the role of pancreas as an endocrine gland?
4. Name the disorders occur to pancreas.

Question 8.
What is the role of Adrenalin in controlling emotions?
Answer:
Adrenalin increases rate of heart beat, causes rise in blood sugar, dilation of coronary artery and dilation of pupil of the eye.

Question 9.
What is the significance of the adrenal gland in the human body?
Answer:
Adrenal gland secrets adrenaline. It helps in

1. Increase heart beat rate
2. Rise in blood sugar
3. Dilation of the coronary artery
4. Dilation of pupil of the eye.

Question 10.
Write the difference between hormone and enzyme.
Answer:

Hormone	Enzyme
1. These are secreted by ductless glands.	1. These are secreted by duct glands.
2. These are travel through blood.	2. These are travel through the ducts.
3. Less in quantity.	3. More in quantity.
4. Reaction is slow.	4. Reaction is fast.
5. Involved in metabolic activities	5. Involve in digestion.
6. Ex: Insulin	6. Ex: Lipase

Question 11.
Observe the following table and answer the questions.

Hormones	Uses
Thyroxine	Normal growth rate, effect on metabolism
Auxins	Cell elongation and differentiation of shoots and roots

i) Name the phytohormone in the table.
ii) Name the hormone which influences growth rate in humans.
Answer:
i) Auxin
ii) Thyroxine.

Question 12.
What questions you will ask a neurologist on function of brain?
Answer:

1. How does alcohol cosumption affect the brain?
2. Which part of brain is responsible for creativity?
3. How do we get fits ? 4) How do we get paralysis?
4. What kind of food should we take to increase?

Question 13.
Label a, b, c, d in the diagram given below and write their functions.
Answer:
a) Sensory Neuron/-Afferent Neuron: These carry messages towards the central nervous system.
b) Motor Neuron /- Efferent Neuron: These carry messages from central nervous system to body parts
c) White Matter
d) Effector Muscles: Respond to stimuli.

Question 14.
Prepare a table showing tropic movements in plants in response to stimuli.
Answer:

SI. No.	Tropic movement	Response to stimuli
1.	Phototropism	Movement towards light.
2.	Geotropism	Respond positively for gravitational force.
3.	Hydrotropism	Roots grow towards presence of water in the soil.
4.	Thigmotropism	Tendrils and climbing plants grow towards support.

Question 15.
Explain two tropic movements with suitable examples.
Answer:

1. Phototropism: Response of plant to light cite example is called phototropism.
   Ex: sunflower
2. Geotropism: Response of a plant to gravitational force Ex: root growth of plant
3. Hydrotropism: Response of root to water availability in the soil.
   Ex : Plants which are growing very close to rocks and walls.
4. Thigmotropism: Response to make contact or touch is called Thigmotropism.
5. Chemotropism: Response to chemical is called chemotropism (Stigma secretes sugary substances)

Question 16.
Write two voluntary functions and two involuntary functions you have observed in your body.
Answer:
a) Examples for voluntary functions:

1. Cleaning the table
2. Playing on the keyboard.

b) Examples for involuntary functions :

1. Salivating when food is kept in the mouth
2. Closing of eyes when bright light is focussed.

Question 17.
Plants show tropic movements in different situations. Give examples.
Answer:

1. Movement of individual parts of plants is possible when they are subjected to external stimuli. This type of response is called tropism or tropic movement.
2. The response of a plant to light is called phototropism. Respond of plants for gravity is called geotropism. Movement of plant towards water is called hydrotropism. The type of response by plants to make contact or touch is called thigmotropism. The response of plants to chemicals is called chemotropism.
3. Pollen grains respond to this stimulus as pollen tubes grow to reach the ovule for fertilization.

Question 18.
Divide the following into groups. Walking, blinking of eye lids, heart beat, laughing, digestion of food and reading. How do you divide them into groups?
Answer:
These can be divided into voluntary actions, involuntary actions and reflex actions.
Voluntary actions: Walking, laughing, reading
Involuntary actions: Digestion of food, heart beat
Reflex actions: Blinking of eye lids

Question 19.
What are ganglia?
Answer:

1. Ganglia or neural ganglia are the structures located in the peripheral nervous system (for example beside the spinal column or near viscera) made of concentration of neuron bodies.
2. Examples of neural ganglia are the ganglia that concentrate cell bodies of sensory neurons in the dorsal roots of the spinal cord and the ganglia of the myenteric plexus responsible for the peristaltic movements of the digestive tube.

Question 20.
Write a brief note on the functioning of sympathetic nervous system.
Answer:

1. This part of the autonomous nervous system increase the activity of an organ as per the need.
2. For example, during running there is an increased demand for oxygen by the body.
3. This is fulfilled by an increased breathing rate and increased heart rate.
4. The sympathetic nervous system works to increase the breathing rate and the heart rate.

Question 21.
Explain briefly about the action of parasympathetic nervous system.
Answer:

1. This part of the autonomous nervous system decrease the activity of an organ and it has calming effect.
2. During sleep, the breathing rate and also the heart rate slows down.
3. This is facilitated by the parasympathetic nervous system.
4. It can be said that the parasympathetic nervous system helps in conservation of energy.

Question 22.
Why are some patients of diabetes treated by giving injections of insulin?
Answer:

1. Insulin is produced by Islets of Langerhans of pancreas.
2. Insulin regulates the level of glucose in the blood.
3. Deficiency of insulin results in disease called ‘diabetes’.
4. Such diabetic patients are given injections of insulin so that the sugar or glucose level in the blood can be controlled.
5. Insulin is now produced in large quantities for the treatment of human sufferers from ‘sugar diabetes’.

Question 23.
What is chemotropism? Explain it with suitable example.
Answer:

1. Response of a plant towards chemicals is known as chemotropism.
2. If we taste the carpel of a flower, it is sweet.
3. Butterflies flutter on flowers for nectar.
4. Ripen stigma secretes sugary substance.
5. This chemical substance stimulates the pollen grain which falls on the stigma.
6. Pollen grains respond to this stimulus as pollen tubes grow to reach the ovule for fertilization.

Question 24.
What are plant growth substances? Give examples.
Answer:

1. Plant growth substances are the chemical (organic) substances which are produced in plants and act at minute concentration on growth and other phisiological functions of plants.
2. There are five major types of plant growth substances. They are auxins, Gibberellins, cytokinins, Ethylene and Abscisic Acid.

Question 25.
What is ethylene? Explain its action.
Answer:

1. Ethylene is a gaseous growth inhibiting substance.
2. Ethylene causes ripening of the fruits.
3. It modifies the growth of the plant by inhibiting stem elongation.
4. It accelerates abscission of leaves, flowers and fruits.

Question 26.
What is Apical dominance?
Answer:

1. In some plants main stem grows by the activity of terminal bud without giving any branches.
2. It means the activity of lateral buds is suppressed and this phenomenon of suppression of the growth of lateral buds by terminal bud is called Apical dominance.

Question 27.
What happens at the synapse between two neurons?
Answer:
At synapse, in between the end of one axon and end of another dendrite electrical impulse sets off the release of some chemicals (neurotransmitter). These chemicals cross the gap or synapse and reach to dendrites of the next neuron and start electrical impulse there.

10th Class Biology 5th Lesson Coordination 4 Marks Important Questions and Answers

Question 1.
i) This diagram belongs to which system of the body?
Answer:
Human nervous system

ii) Name the parts A and B.
Answer:
A. Cerebellum
B. Medulla oblongata

iii) The part ‘C is endocrinal gland. This is called master gland. What is the name of this gland?
Answer:
Pituitary gland

iv) Which part in this diagram is useful to solve problems and puzzles?
Answer:
Cerebrum

Question 2.
Name the important parts of the brain and write the functions of fore-brain.
(OR)
Write in a tabular form the different parts of human brain and their functions.
Answer:

1. Brain has the following divisions.
   1. Fore brain – Cerebrum, diencephalon
   2. Mid brain – Optic lobes.
   3. Hind brain – Cerebellum, medulla.
2. Functions of the various parts of the brain.
   

   Parts of the brain	Functions
   Cerebrum	i)    Seat of mental abilities, controls thinking memory, reasoning, perception, emotions and speech. ii)    Interprets sensations and responds to cold, heat, pain and pressure.
   Diencephalon	i)     Relay centre for sensory impulses, such as pain, temperature and light. ii)    Reflex centre for muscular activities. iii)     Centre for certain emotions such as anger. iv)     Centre for water balance, blood pressure, body temperature, sleep and hunger. v)    The hypothalamus controls the pituitary gland, which functions as the master gland.
   Mid brain	i) It relays motor impulses from the cerebral cortex to the spinal cord and relays sensory impulses from the spinal cord to thalamus, reflexes for light and hearing.
   Cerebellum	i)     Maintains posture, equilibrium and muscle tone. ii)    Coordinates voluntary movements initiated by cerebrum.
   Medulla oblongata	i)     Contains centre for cardiac, respiratory and vasomotor activities. ii)    Coordinate reflexes like swallowing, coughing, sneezing and vomiting.

Question 3.
Observe the following diagram. What does it represent? Explain the process in a flow-chart.
Answer:

Question 4.
Read the following table:

Part of the Brain	Functions
a) Olfactory lobes	Sense of smell
b) Cerebrum	Mental abilities, memory, reasoning, perception, emotion and speech, respond to cold, heat, pain and pressure
c) Diencephalon	Controlling emotions, center for water balance, blood pressure, sensory impulses such as pain, temperature and light, sleep and hunger.
d) Cerebellum	Maintains posture, equilibrium and muscle tone, co­ordinates voluntary movements initiated by cerebrum.

Now, identify the part of the brain which participate in the below situations.

a) Ravi is an intelligent boy. He can remember the things for a long time.
Answer:
Cerebrum

b) The drunken man does not walk properly.
Answer:
Cerebellum

c) Identifies the food items without seeing which are being prepared in the kitchen
Answer:
Olfactory Lobes

d) Naveen lost his money purse while coming to the school. But he is not crying.
Answer:
Diencephalon

e) It is time for lunch.
Answer:
Cerebrum

f) I cannot tolerate this type of heat in the summer.
Answer:
Cerebrum

g) Catching the ball perfectly.
Answer:
Cerebellum

h) There may be a drainage behind the house.
Answer:
Olfactory Lobes

Question 5.
Look at the picture and answer the questions:
a) To which system does the diagram belong ?
Answer:
The diagram belongs to T.S. of Spinal cord (peripheral).

b) What is the name of A, B parts ?
Answer:
A – Dorsal Root,
B – Ventral Root

c) What is ‘C’ ? What is its function ?
Answer:
C – Association neuron
It analyse the information – and send the order (function) through motor neuron to muscle.

d) Through which horn the sensory nerve enters ?
Answer:
Sensory nerve enters through dorsal horn.

Question 6.
Fill the following table related to Endocrine glands.

1.	Name of the endocrine gland	Location	Hormone secreted	Response of body to that hormone
2.
3.
4.

Answer:

S.No.	Name of endocrine the gland	Location	Hormone secreted	Response of body to that hormone
1.	Pituitary	Floor of brain	Somatotropin	Growth of bone.
			Gonadotropin	Activity of ovary and testis.
2.	Thyroid	Neck	Thyroxine	General growth rate and metabolic activity.
3.	Ovary	Lower abdomen	Estrogen	Growth of the uterus and skeleton of the pelvis.
4.	Testis	Scrotal sac	Testosterone	Growth of male secondary sexual characters.

Question 7.
Observe the following table and answer the questions.

Division -1	Division – II
Auxins	Adrenalin
Gibberellins	Testosterone
Ethylene	Estrogen
Abscisic Acid	Thyroxin
Cytokinins	Growth Hormone

a) On what basis the above classification done?
Answer:
Hormones in animals and hormones in plants.

b) From which gland is Adrenalin released?
Answer:
Adrenal gland.

c) Which hormone is responsible for closing of stomata?
Answer:
Abscisic Acid (ABA)

d) What are the functions of Auxins?
Answer:
Cell elongation and differentiation of shoots and roots.

Question 8.

A) What does the given picture represent?
B) Name the parts A, B and C.
C) What carries the nerve impulse to the spinal cord?
D) Wrhat is the function of association neuron?
Answer:
A) The given picture represents
T.S. of Spinal cord (peripheral).
B) A – Dorsal root B – Ventral root C – Association neuron
C) Through dorsal root the nerve impulse reaches the spinal cord.
D) Association neuron analyses the information and sends the order through motor neuron to muscle.

Question 9.
The following table is about parts of brain and their functions. Read it and fill the blanks.

Part of the brain	Functions
Cerebrum
	Centre for certain emotions such as anger
Midbrain	It relays motor impulses from the cerebral cortex to the spinal cord and relays sensory impulses from the spinal cord to the thalamus, reflexes for sight and hearing.
	Maintains posture, equilibrium and muscle tone.
Medulla oblongata

Answer:

Cerebrum	i) Site of mental abilities, controls thinking, memory, reasoning, perception, emotions and speech. ii) Interprets sensations and responds to cold, heat, pain and pressure.
Diencephalon	Centre for certain emotions such as anger.
Midbrain	It relays motor impulses from the cerebral cortex to the spinal cord and relays sensory impulses from the spinal cord to the thalamus, reflexes for sight and hearing.
Cerebellum	Maintains posture, equilibrium and muscle tone.
Medulla oblongata	i) Contains centre for cardiac, respiratory and vasomotor activities. ii) Coordinates reflexes like swallowing, coughing, sneezing and vomiting.

Question 10.
Ramya ran away shouting loudly after seeing a snake on the way to school. Arrange the events involved in this situation in the correct order and rewrite it.
i) Brain receives the information, analyses and produces the reponse.
ii) Sensory nerves carry the information from sense organs to brain,
iii) Effector muscles exhibit the response.
iv) Sense organs receive the information from the environment.
v) Motor nerves carry the response from the brain to effector muscles.
Answer:
1-d, 2-b, 3 -a, 4-e, 5-c
d) Sense organs receive the information from the environment.
b) Sensory nerves carry the information from sense organs to brain,
a) brain receives the information analyse and produces the response.
e) Motor nerves carry the response from the brain to effector muscles.
c) Effector muscles exhibit the response.

Question 11.
Observe the following information and answer the following questions.

S.No.	Hormones	Uses
1.	Auxins	Cell elongation and differentiation of shoots and roots.
2.	Abscisic acid	Closing of stomata, seed dormancy
3.	Ethylene	Ripening of fruit
4.	Cytokinins	Promote cell division, promote sprouting of lateral buds, delay ageing of fruits.

i) What do we call the hormones that are present in plants?
Answer:
We call phyto hormones which are present in plants.

ii) Name the hormones which are helpful in the growth of the plants.
Answer:
Auxins, gibberellins, cytokinins are helpful in the growth of the plants.

iii) Farmers keep carbide powder in between raw mangoes. What might be the reason? What will be the end result after 3 to 4 days?
Answer:
Carbide release Ethylene, which promotes the fruit ripening. After 3 or 4 days fruits will ripen.

iv) Plants also respond like animals. Do you agree with this statement? Support your answer.
Answer:
Yes, plants also respond like animals. They shut off leaves in summer, germinate in rainy season, blooms according to seasons.

Question 12.
Read the following table and answer the questions given below.

S.No.	Name of the gland	Location	Hormone secreted	Response of the body to hormone
1.	Pituitary	Floor of brain	Somatotropin	Growth of bone.
			Gonadotropin	Activity of ovary and testis.
2.	Thyroid	Neck	Thyroxine	General growth rate and metabolic activity.
3.	Ovary	Lower abdomen	Estrogen	Growth of the uterus and skeleton of the pelvis.
4.	Testis	Scrotal sac	Testosterone	Growth of male secondary sexual characters.

i) Write the importance of glands and hormones.
Answer:
Glands and hormones controls and coordinates various functions of the body with nervous system.

ii) Which hormone is responsible for growth of bone?
Somatotropin is responsible for growth of bone.

iii) What happens if testosterone is not secreted?
Secondary sexual characters in male are not developed if testosterone is absent.

iv) Where does the gland that secretes thyroxine is located?
Thyroid gland which secretes thyroxine is located near the neck.

v) Which glands are common in male and female?
Pituitary, thyroid, adrenal glands, parathyroid and pancreas are common in male and female.

Question 13.
Explain the different types of adaptations in plants with suitable examples.
Answer:

1. Most plants can aerate their roots bj’ taking in the oxygen through the lenticels or through the surface of their root hairs.
2. But plants which have their roots in very wet places, such as ponds or marshes, are unable to obtain oxygen.
3. They are adapted to these water-logged conditions by having much larger air spaces which connect the stems with the roots, making diffusion from the upper parts much more efficient.
4. The most usual adaptation is to have a hollow stem.
5. The problem of air transport is more difficult for trees.
6. An exception is the mangrove tree of the tropics which have aerial roots above the soil surface and takes in oxygen through these roots.

Question 14.
Karthik is suffering from excess sugar in urine and Varun is suffering from repeated dilute urination. What are the reasons for these diseases ? Explain.
Answer:

1. Excess sugar in urine condition is known as diabetes milletus. (sugar diabetes)
2. Repeated dilute urination is known as diabetes insipidus, (diuretic condition)
3. Deficiency of insulin causes high level sugar in the blood and urine. It leads to diabetes milletus (Sugar diabetes).
4. Vasopressin maintains osmotic concentration of body fluids. Deficiency of vasopressin causes excessive repeated dilute urination it is called as diabetes insipidus.

Question 15.
Analyse the following information and answer the questions.

S.No	Organ	List-1 Effect of Nervous system	List-2 Effect of Nervous system
1.	Eye	Dialates pupil	Constricts pupil.
2.	Mouth	Inhibits salivation	Stimulates salivation
3.	Lungs	Relaxes bronchi	Constrict bronchi.
4.	Heart	Accelerates heart beat	Heart beat to normally.
5.	Blood vessels	Increase blood pressure	Decrease blood pressure.
6.	Pancreas	Inhibits Pancreas activity	Stimulates Pancreas activity.

i) Write two functions of Sympathetic Nervous System.
ii) Name two organs that are influenced by Parasympathetic Nervous System.
iii) Name the Nervous system mentioned in the table that increases the blood pressure.
iv) What systems constitute Autonomous Nervous System?
Answer:
i) Dilates pupil, inhibits salivation, relaxes branchi, accelerates heart beat, etc.
ii) Eye, heart, pancreas, etc.
iii) Sympathetic nervous system
iv) Sympathetic and para sympathetic nervous system.

Question 16.
Explain the Phytohormones which control growth in plants.
Answer:
Major plant hormones and their action:

Hormones	Uses
Auxins	Cell elongation and differentiation of shoots and roots.
Cytokinins	Promote cell division, promotion of sprouting of lateral buds, delaying the ageing in leaves, opening of stomata.
Gibberellins	Germination of seeds and sprouting of buds; elongation of stems; stimulation of flowering; development of seedless fruits, breaking the dormancy in seeds and buds.
Abscisic acid	Closing of stomata; seed dormancy, promoting aging of leaves.
Ethylene	Ripening of fruit.

Question 17.
Analyse the table and answer the following questions.

Sl.No.	Part of Brain	Functions
1.	Cerebrum	Mental abilities, memory, speech.
2.	Diencephalon	Sensory impulses, emotional impulses, muscular activities.
3.	Midbrain	Reflexes of sight and hearing.
4.	Cerebellum	Equilibrium.
5.	Medulla oblongata	Respiratory, cardiac centres, blood pressure.

i) Which part of the brain recollects the childhood incidents?
Answer:
Cerebrum.

ii) Write two parts of hind brain.
Answer:
Cerebellum, medulla oblongata.

iii) Name the part of the brain that will not function in drunken person.
Answer:
Cerebellum.

iv) Name the part of the brain that controls involuntary actions.
Answer:
Medulla oblongata.

Question 18.
Write contrasts and comparisons of the style of response in plants and animals to the stimuli.
Answer:

1. Both plants and animals react to various stimuli around them. But the method of responding to stimuli is not similar in plants and animals. .
2. Higher animals respond to stimuli because they have a nervous system and an endocrine system.
3. Plant do not have a well defined nervous or endocrine system. They do have some mechanism of control by means of some chemicals or hormones.
4. Plants can sense the presence of stimuli like light, heat, water, touch, pressure, chemicals, gravity, etc.
5. The hormones present in the plants called phytohormones control response towards the stimuli. Phytohormones coordinate the activities of the plant usually by controlling one or the other aspect of the growth of the plant.

Question 19.
Read the below paragraph and write answers.

There is systematic method in showing response to stimuli. There is different stages in it. First stage starts with the response recognising the changes in outside or inside of the body atmosphere with recognising the stimuli. Transmitting the received information is second stage, analysing that information is third stage and showing correct response to that stimuli is the last stage.

a) What does this information shows?
b) Convert the above information into flow chart.
c) Write about the mechanism that conducts this action.
Answer:
a) It shows the systematic method in showing response to stimuli.

b)

c) Nervous system can sense the changes inside and outside the body through specialised cells called Receptors. This information in the form of small electrical currents is sent to brain and analysed and responses are generated in the nervous system. These responses once again in the form of small electrical currents are conveyed to the appropriate organs such as muscles and glands at a greater speed. Nervous system may store this information for future use.

Question 20.
See the below action. What does it indicate? Explain with an example.
Answer:

1. It indicates the stimulus – response action. This stimulus response can be explained with an example.
2. Suppose a mosquito is biting you on your arm. Mosquito bite is stimulus.
3. The receptor in the skin responds and send the information in the form of electrical impulses through sensory nerve to spinal cord or brain.
4. Brain or spinal cord analyses the information that the mosquito bite is causing pains.
5. The brain or spinal cord sends the message through motor nerve to the effector organ i.e., hand to kill the mosquito.
6. As per the message our hand immediately hits the mosquito and kills it.

Question 21.
Rangaiah is not feeling well. The following table is the results of tests. Analyse the table.

Tests	Present Status	Normal Range
Blood Test
1. Blood Pressure	160/90	120/80
2. Glucose (Fasting)	120	60-100
3. Glucose (Post Lunch)	220	160-180
4. Bilirubin	1.0	0.1 – 0.8
Urine Test
1. 24 hours protein	150 mg	100 mg
2. Sodium	140	125-250

Write answers for the following questions.
i) How can you state that Rangaiah is diabetic?
Answer:
After blood test it was found that level of glucose (Fasting) is 120 whereas the normal range is 60 -100. After lunch the level of glucose in blood of Rangaiah further raised to 220, the normal being between 160 – 180. This shows that Rangaiah is diabetic.

ii) What are the tests to know about Bilirubin?
Answer:
We can know about bilirubin by blood test.

iii) What do you understand from the above report?
Answer:
It shows that Rangaiah is diabetic and his systolic pressure is slightly high. The levels of bilirubin in blood also slightly high, almost normal range. Urine test shows sodium levels are at normal range but 24 hours protein is much higher than normal levels.

iv) What questions do you ask the doctor on the above report?
Answer:

1. What are symptoms shown by Rangaiah as diabetic patient?
2. What are the ways to control sugar in the blood?
3. Which hormone is responsible for raise of glucose in the blood?
4. How sodium maintains blood pressure at normal levels?
5. What is the role of bilirubin in digestion?

Question 22.
What is reflex arc? Write the components of reflex arc and their functions.
Answer:

1. The structural and functional unit that carries out reflex action is called a reflex arc.
2. It consists of five components.
3. They are receptor, a sensory nerve, a association neuron, a motor nerve and an effector organ.
   

   SI. No.	Component of reflex arc	Functions
   1.	Receptor	Receives information and generates impulses.
   2.	Sensory neuron (Afferent)	Carries information from the receptor to the interneurons in the spinal cord.
   3.	Interneuron (Association neuron)	Processes the information and generates responses
   4.	Motor neuron (Efferent)	Carries the information from the spinal cord to the effector organ.
   5.	Effector organ	Receives the information from the efferent neuron and shows the appropriate responses.

Question 23.
What are endocrine glands ? What are their functions?
Answer:
Endocrine glands:

1. Endocrine glands are the ductless glands.
2. They secret complex organic substances called hormones directly into the blood.
3. Hormones are transported through blood to different tissues.
4. Their secretions act as biochemical messengers in the body.

Functions:

1. The hormones secreted by these glands play an important role in co-ordinating various organ systems.
2. Hormones can increase or decrease the metabolism and synthesis of substances like proteins, carbohydrates and lipids.
3. Irregular functioning of these glands may lead to serious diseases.
4. The quantity of hormone required is very minimum (1/10,00,000 gram).
5. A slight increase or decrease may brings out large changes in the target tissue.

Question 24.
How does a nerve impulse travel through the body?
Answer:

1. The information acquired at the dendritic tip of a nerve cell sets off a chemical reaction that creates an electrical impulse.
2. This impulse travels from the dendrite to the cell body and then along the axon to its end.
3. At the end of the axon the electrical impulse sets off the release of some chemicals.
4. These chemicals cross the gap or synapse and start a similar electrical impulse in a dendrite of the next neuron.
5. A similar synapse finally allows the delivery of such impulse from neurons to other cells such as muscles or glands.

Question 25.
How is the brain anatomically divided?
Answer:

1. The cerebrum is divided into two cerebral hemispheres, the right and left.
2. Each hemisphere is made of four cerebral lobes. Frontal lobe, parietal lobe, temporal lobe and occipetal lobe.
3. Each cerebral lobe contains the gray matter and the white matter.
4. The gray matter is the outer portion and is made of neuron bodies, the gray matter is also known as the cerebral cortex.
5. The white matter is the inner portion and it is white because it is in the region where axons of the cortical neuron pass.

Question 26.
What are the divisions of the autonomous nervous system?
Answer:

1. Ganglia near the vertebral column are connected to the spinal cord by nerves.
2. The two divisions of autonomic nervous system are sympathetic nervous system and parasympathetic nervous system.
3. The sympathetic nervous system is formed by the chain of ganglia on either sides of the vertebral column and the associated nerves.
4. The parasympathetic nervous system is formed by the nerves arising from the ganglia of the brain and the posterior part of the spinal cord.
5. These together constitute the autonomous nervous system which is the part of the peripheral nervous system consisting of twelve pairs of cranial nerves and thirty one pairs of spinal nerves.

Question 27.
What is autonomous nervous system? Explain how it controls voluntary functions with an example.
Answer:

1. The peripheral nervous system that controls involuntary functions of the body is known as Autonomous nervous system.
2. It has voluntary control of muscles of some areas of skin and the skeletal muscle.
3. For example when we enter a dark room we can not see anything immediately. Slowly we are able to see the things around us in the room.
4. This is because of increase in diameter of pupil, which allows more light in.
5. When we come out of the dark room into broad day light the diameter of the pupil decreases allowing less light to enter into the eyes.
6. Both these functions occur under the influence of the autonomous nervous system.

Question 28.
What is the master gland in the human body? What are the functions of the hormones it secretes? (OR)
Why is pituitary gland known as master gland? How does it control all the other glands in the body?
Answer:

1. Pituitary gland is known as the master gland of the body as it controls the functions of all the other endocrine glands.
2. It serves as a link between nervous system and endocrine system.
3. The hormones secreted by pituitary gland and their functions are as follows.

Hormone	Response of the body to hormone
a) Somatotrophin	Growth of bones
b) Thyrotrophin	Activity of thyroid gland
c) Gonadotrophin	Activity of ovary and testis
d) Andrenocortico trophic	Stimulates secretion from adrenal cortex
e) Luteinising hormone	In males – secretion of testosterone; In females – Ovulation, development of Corpus Luteum and secretion of progesterone.

Question 29.
What are the differences between the manner in which movement takes place in a sensitive plant and the movement of our legs?
Answer:

1. The stimulus of touch causes the response in a sensitive plant Mimosa pudica.
2. Droping of the leaves takes place due to change in osmotic pressure at the base of the leaf.
3. When the stimulus is over, the osmotic pressure increases causing the leaf to become normal.
4. This is not a growth related movement.
5. It is not connected with the direction of the stimulus.
6. Nerve messages in the form of electrical impulse reaches the leg muscles from the brain.
7. On reaching the leg muscles, the muscles contract causing the movement of the leg.

Question 30.
What is the need for a system of control and coordination of organisms? (OR)
How is control and coordination brought in organisms?
Answer:

1. The various physiological processes in an organism are closely linked and depen¬dent on each other.
2. The linking together of body activities in time and space is called coordination.
3. Without coordination, the activities of the body would be disturbed a lot.
4. For example when eating food at meal, the position of food is recorded by the eyes and as a result of this information the arms are moved to the right place to pick it up with precision and accuracy.
5. As the food is raised to the mouth, the latter opens to receive it. Chewing movements commence and saliva is secreted.
6. At the moment of swallowing, epiglottis closes trachea.

Question 31.
What is the experiment conducted by Charles Darwin and Francis Darwin? What is their conclusion?
Answer:

1. Charles Darwin and his son Francis Darwin performed some experiments on phototropism.
2. They covered the terminal portion of the tip of stem (coleoptile) with a cylinder of metal foil.
3. Exposed the plant to light coming from the side.
4. The characteristic bending of the seedling did not occur.
5. If light was permitted to penetrate the cylinder, bending occurred normally.
6. They concluded that when seedlings are freely exposed to a lateral light some influence is transmitted from upper to the lower part causing the material to bend.

Question 32.
What are the different types of tropisms found in plants?
Answer:

1. The different types of tropisms found in plants are phototropism, geotropism, chemotropism, hydrotropism and thigmotropism.
2. Different stimulus and type of tropism.
   Stimulus Type of tropism
   Light – Phototropism
   Gravity – Geotropism
   Chemical substance – Chemotropism
   Water – Hydrotropism
   Touch – Thigmotropism

Question 33.
Describe the story of invention of insulin. (OR)
Collect the information about insulin from internet and other sources and report on it.
Answer:

1. In Latin “insula” means an Island.
2. In 1868 Paul Langerhans of Germany working on the structure of Pancreas found Islets of Langerhans specialised cells richly supplied with blood vessel.
3. But the function of pancreas remained unknown.
4. Many others interested in the function of pancreas found that its removal from the body of an experimental animal would lead to the development of disease called ‘sugar diabetes’ (or) diabetes mellitus.
5. Diabetes is a condition in which the amount of free sugar in the blood and in the urine is abnormally high.
6. Later scientists found that when they tied the pancreatic duct that emerge from the duodenum caused the degeneration of pancreas but not Islets of Langerhans.
7. Moreover the animal would not develop diabetes. This was really a strong evidence that the level of blood sugar is linked with the Islet cells.
8. By 1912 workers were convinced that the Islets produced a secretion which directly liberated into the blood.
9. Ten years later in Toronto, Banting, Best and Macleod finally succeeded in extracting insulin from degenerate animal pancreas whose ducts to the intestine had been tied.
10. Insulin is now produced in large quantities for the treatment of human sufferers diabetes, to whom it is administered by injection into the skin.

Question 34.
Compare and contrast the nervous and hormonal mechanism for control and coor-dination in animals.
Answer:

Nervous system	Hormonal system
1) Nervous system has a network of nerves.	1) Hormone system does not have such a network in the body.
2) Nervous impulses pass from the receptors to the central nervous system and then to the effectors, through nerve fibers.	2) Hormone system does not have such a network in the body. Hormones pass from the endocrine glands through blood.
3) Nerve impulses reach only the cells required to respond.	3) Hormones reach all the cells but special cells on the target organs using special molecules on their surfaces recognize the information and act.
4) There is no feedback mechanism in generating electrical impulses.	4) The timing and amount of hormones released are dependent on feedback mechanism.

Question 35.
Write brief notes on Ivan Pavlov’s experiment on dog to demonstrate conditioned reflexes.
Answer:

1. Conditioned reflexes are not inherited.
2. Ivan Pavlov, a Russian scientist did experiments on conditioned reflexes. His experiments on dogs have become very famous.
3. When the dog sees food, it secretes salvia. He rang a bell whenever the dog was given food.
4. After doing this for few days he noticed that the dog secretes salvia when it hears the bell even if the food is not given.
5. In otherwords dog associated the sound of the bell with the food and assumes that whenever the bell rings food is given.
6. In expectation of food, saliva start flowing from its mouth. Human beings are no exception to this.
7. For example, standing in attention when you hear National Anthem.

Question 36.
Collect information about the major plant hormones from library or internet?
Answer:
Some major plant hormones and their action are given in the following table.
Major plant hormones and their action.

Hormones	Uses
Abscisic acid	Closing of stomata; seed dormancy.
Auxins	Cell elongation and differentiation of shoots and roots.
Cytokinins	Promote cell division, promotion of sprouting of lateral buds, delaying the ageing in leaves, opening of stomata.
Ethylene	Ripening of fruit.
Gibberellins	Germination of seeds and sprouting of buds; elongation of stems; stimulation of flowering; development of fruit, breaking the dormancy in seeds and buds.

Question 37.
What are auxins? How do they affect plant growth?
Answer:

1. Auxins are phytohormones which promote longitudinal growth in plants.
2. The term auxin usually refers to a chemical compound called Jndole Acetic Acid (IAA) which is the principal nature auxine.
3. IAA promotes growth and elongation of stems, roots and enlargement of many fruits.
4. Auxins are known to loosen the cellulose frame work of cell wall which helps in cell enlargement.
5. Auxins promotes cell division in vascular cambium and also root initiation.
6. Auxins are also responsible for bending of plants in response to light (phototropism) and also to the gravity stimulus (Geotropism).
7. Auxin is responsible for Apical dominance.
8. A large number of auxins are synthesized by artificial methods in chemical laboratories.
9. Substances like Naphthalene Acetic Acid (NAA) and Indole Butyric Acid (IBA) are used for inducing roots in cuttings.
10. Auxin spray can prevent premature fruit drop .
11. Auxin is also known to inhibit the abscission of leaves and fruits.

Question 38.
What is the role of Gibberellins in plant growth and development?
Answer:

1. Gibberellins has a significant effect on stem elongation.
2. It also increases the leaf lamina area. This is due to stimulation of cell division and cell elongation to both leaves and stem.
3. It leads to the formation of seedless fruits.
4. Gibberellins along with auxins promote cell elongation and leaf expansion.
5. Parthenocarpy is induced in fruits like apple and pear with spray of Gibberellins.
6. These substances are also known to induce enzymes like amylase, protease, lipase, etc. at the on set of seed germination and break the seed dormancy.
7. These substances are used for fruit setting and also for growing seed less fruits.
8. In beverages industry gibberellin is used to stimulate amylase activity in barley seeds. This is known to enhance the malting of barley grains.

Question 39.
What are the functions of cytokinins?
Answer:

1. Cytokinins are capable of stimulating cell division along with auxins.
2. They promote cell elongation.
3. They have ability to delay the pocess of ageing in leaves.
4. Cytokinins can prolong the life of fresh leaf crops like cabbage, spinach.
5. They are also used for keeping the flowers fresh.
6. Cytokinins are most effective in breaking dormancy of buds and seeds.
7. The levels of cytokinins decrease in senescing leaves.

Question 40.
What is ABA? Explain its function in the plant.
Answer:

1. ABA means Abscisic acid. It is the plant growth inhibiting substance.
2. It induces dormancy in buds, tubers and many seeds.
3. ABA is responsible for the formation of separation layer or abscission layer between main plant and the leaf or between plant and flower or fruit. It results in the falling of leaves, fruits and flowers.
4. It prevents the water loss during drought conditions by closing the stomata.

Question 41.
Draw a diagram of Reflex area and describe the functions of different parts of Reflex arc.
Answer:
Functions of different parts of Reflex arc : Reflex arc consists of a receptor, a sensory nerve (afferent) an association neuron or inter neuron, motor nerve (effferent) and a effector organ.

S.No.	Component of the Reflex arc	Function
1.	Receptor	Receives information and generates impulses.
2.	Sensory (Afferent) nerve	Carries information from the receptor to the inter neurons in the spinal cord.
3.	Inter neurons	Processes the information and generates responses
4.	Motor (efferent) nerve	Carries the information from the spinal cord to the effector organ.
5.	Effector organ	Receives the information from the efferent neuron and shows the appropriate response.

Question 42.
Write a brief account on peripheral nervous system.
Answer:

1. The peripheral nervous system consists of nerves that arise from the brain and
   spinal cord; and a vast system of dorsat and ventral root nerve cell heads.
2. The peripheral nervous system has 43 pairs of nerves.
   
3. Of these 12 pairs are called cranial nerves and the rest of 31 pairs are called spinal nerves.
4. Nerves attached to the spinal cord have two types of connections or roots – One to the back or the dorsal side and other to front or the ventral side of cord.
5. The peripheral nervous system can either involuntarily control several functions of regions like our internal organs, blood vessels, smooth and cardiac muscles. So it is called autonomous nervous system.

Question 43.
Write briefly about the spinal cord. (OR)
Describe the transverse section of spinal cord with the help of a diagram.
Answer:

1. Spinal cord is a long and cylindrical structure.
2. It passess through vertebral column extending all along the dorsal surface of trunk.
   
3. In other words, vertebrae of the vertebral column protect the spinal cord from injuries.
4. In a cross section of the spinal cord, the grey matter appears like butterfly or in the shape of letter ‘H’.
5. Each segment of the ‘H’ shaped grey matter is called a horn.
6. The upper horns are called dorsal horns, and the lower horns are called ventral horns.
7. In the middle of the grey matter is a canal called spinal canal.
8. It runs all along the length of spinal cord and is filled with cerebrospinal fluid.
9. From the sides of spinal cord, 31 pairs of nerves take their origin and supply branches to various parts of the body.

Question 44.
Describe an experiment to demonstrate hydrotropism. (OR)
The roots of a plant move or grow towards water in the soil. How do you prove this with the help of an experiment ?
Answer:
Aim: To prove that roots grow towards water.
Apparatus or materials: Two glass troughs, soil, two similar plants, clay pot, water.

Procedure:

1. Take two glass troughs A and B,
2. Fill each one of them with two thirds of soil,
3. Plant a tiny seedling in trough A.
   
4. In trough B, plant a similar seedling and place a small clay pot inside the soil.
5. Water the soil in the trough A daily and uniformly.
6. Do not water the soil in trough B, but put some water in the clay placed in the soil.
7. Leave both the troughs for a few days.

Observation: On examining the roots later, it will be found that the root in the trough B has bent towards the source of water. Roots in trough A grew normally straight. Result: The growth of roots towards water is known as hydrotropism. In this experiment roots bent towards water. By this experiment it was proved that roots always grow towards water.

Question 45.
Observe the diagram and answer the following questions.
i) To which organs of the body do the nerves go from the ganglions near the vertebral column ?
Answer:
Eyes, salivary glands, heart, lungs, liver, stomach, gall bladder, intestine, adrenal gland, sex organs are the body parts, the nerves go from the ganglions near the vertebral column.

ii) Which are the organs that receives nerves starting from the brain ?
Answer:
Nose, eye, tongue, ear, head, neck and shoulder receive nerves from the brain.

iii) Which are the organs whose activities are influenced by the sympathetic nervous system?
Answer:
Eyes, lungs, kidneys, gastro intestinal tract, heart, stomach, sweat glands, sex organs, adrenal gland, salivary glands.

iv) Which tire the organs whose activities are influenced by the parasympathetic nervous system ?
Answer:
Eye, lungs, kidneys, gastro intestinal tract, heart, stomach, sweat glands, sex organs, adrenal gland, salivary glands.

v) What do you understand about the functions of parasympathetic nervous system ?
Answer:

1. The major functions of parasympathetic nervous system is to keep the body in its normal state and it is called as rest and digestive system or feed or breed system.
2. The function of parasympathetic nervous system is to restore the body to its nor¬mal functioning after all the stress is gone.
3. The parasympathetic nervous system helps the body to do simple things such as breathing regularly, excreting hormones, eating and digesting food.
4. It also keeps a person alive when sleeping.

vi) What do you understand about the functions of sympathetic nervous system ?
Answer:

1. The major functions of the sympathetic nervous system is to activate the response of the body during stressful situation including the fight or flight mechanism of the body.
2. Sympathetic nervous system is essentially responsible for helping the body to get ready for action or feeling.
3. It dilates the pupil so one can see better especially in the dark, it increases heart rate so that to increase supply of oxygen to the muscles, decreases digestion so that the energy be better utilized for fighting and so on.

Question 46.
Describe the structure of brain with the help of a neat diagram.
Answer:

1. Proportionate to the body size, the human brain is the largest of all animals.
2. The brain is present in the hard bony box like structure called cranium.
   
3. It is covered by three layers called the meninges. The meninges are continued and cover the spinal cord as well.
4. The space between the inner layers is filled with fluid called cerebro – spinal fluid.
5. It serves as a shock – absorbing medium and protects the brain against shocks / jerks along with meninges and cranium.
6. The nerve cell bodies together with capillaries form a mass called grey matter while the myelinated axons form white matter.
7. The grey matter is in the outer layers while the white matter is present towards inner layers.

Question 47.
Describe the structure of cerebrum.
Answer:

1. Fore brain is the largest part of the brain. It is also called CEREBRUM.
2. A deep groove in the middle of the cerebrum divides into two equal halves.
3. Each calf is called as a cerebral hemisphere.
   
4. Right and left cerebral hemispheres are connected each other by a bundle of axon.
5. The outer portion of the cerebral hemisphere is gray in colour and is called CEREBRAL CORTEX.
6. There are several ridges called GYRI and the grooves are called SULCI.
7. They increase the surface area of the cortex in order to accumulate more number of neurons.
8. In the cerebral cortex, there are centres to receive and analyse various informations like visual (sight), auditory (hearing), olfactory (smell), etc.
9. Three very deep grooves present across each cerebral hemisphere divides it into four lobes. FRONTAL, PARIETAL, TEMPORAL, and OCCIPITAL LOBES.

Question 48.
Write a brief account of Adrenal glands.
Answer:
There are two adrenal glands one on the top of each kidney. Adrenal gland has 2 parts.

1. Cortex – outer part
2. Medulla – Inner part

i) Adrenal cortex: Adrenal cortex secretes two hormones i) cortisol and ii) Aldosterone
a) Cortisol regulates the protein, fat and carbohydrate metabolism.
b) Aldosterone increases the re-absorption of water and sodium in the kidney. It regulates the sodium levels in the body.

ii) Adrenal medulla: It secretes a hormone called Adrenaline at times of physical and mental stress. It is secreted in conditions like:

1. fall in blood sugar levels
2. When the person is injured.
3. When exposed to cold conditions
4. Suffering from pain

The hormone helps in facing such as situation. Therefore it is called the hormone of FIGHT or FLIGHT.

Question 49.
What is feedback mechanism? Illustrate with an example.
Answer:

1. It is necessary that the hormones are secreted by the endocrine glands in our body in precise quantities which are required for the normal functioning of the body.
   
2. This means there should be some mechanism to regulate the production and release of hormones in the body.
3. For example, anger is always short lived factor and adrenalin is the hormone responsible for anger.
4. When the levels of adrenalin in the blood came down slowly, we come to normal state.
5. When we are afraid the rate of heart-beat increases, the breathe rate will be faster, blood pressure increases.
6. After sometime we come to normal state only when we reach a safe spot.
7. The timings and amount of hormones released by endocrine gland is controlled by the feed back mechanism, which is in build in our body.

Question 50.
Write short note on simple goitre. (OR)
What happens if we do not take sufficient amounts of iodine in food? (OR)
Why are people advised to take iodised salt in the food they eat?
Answer:

1. Iodine is required for the synthesis of thyroxine in the body.
2. If there is a reduced intake of iodine in food, it hinders the formation of thyroxine and results in increase the size of the thyroid gland.
3. This results in the enlargement of neck. This condition is called simple goitre.
   

AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 7 Coordination in Life Processes.

AP State Syllabus SSC 10th Class Biology Important Questions 7th Lesson Coordination in Life Processes

10th Class Biology 7th Lesson Coordination in Life Processes 1 Mark Important Questions and Answers

Question 1.
Complete the following table.
Answer:

Question 2.
What is the apparatus used in your class, while performing the demonstration of peristaltic movement in Oesophagus?
Answer:
a) A piece of waste cycle tube.
b) Oil for lubrication.
c) Potatoes.

Question 3.
You have conducted an experiment to prove that HC1 secreted in our stomach, does not harm walls of the stomach. Write the apparatus used in that experiment.
Answer:
Apparatus: Green leaves, petroleum jelly, weak acid.

Question 4.
What will happen, if there is no diaphragm in the human body?
Answer:

1. Diaphragm flattens during inhalation, thus increasing the volume of the thoracic cavity.
2. If the diaphragm is absent the inhalation and exhalation become very difficult in human beings.

Question 5.
What happens if the direction of peristalsis is not reversed in animal like cow?
Answer:
If the direction of peristalsis is not reversed (rumination is not done) in animal like cow, the food will not be masticated in the mouth and fermentation of the food with the micro-organisms in the stomach will not be taken place.

Question 6.
What happens if there is no mucus in the Oesophagus?
Answer:

1. The walls of the food pipe secrete a slippery substance called mucus.
2. Mucus lubricates and protects the oesophageal walls from damage.
3. This helps the food bolus to slide down easily in the tube.
4. If there is no mucus, lubrication will not occur for the food bolus to slide and walls get damage.

Question 7.
Which part of small intestine absorbs digested food?
Answer:
Microvilli/villi.

Question 8.
Name the chemical which is used to test the action of saliva on flour (ata).
Answer:
Iodine Solution.

Question 9.
What happens, if there is no peristaltic movement in Oesophagus?
Answer:

1. The food won’t slidedown in the oesophagus.
2. The digestion of food won’t takes place in the stomach and small intestine.

Question 10.
Number of Neurons present in enteric Nervous System?
Answer:
Number of neurons present in enteric nervous system are 100 millions.

Question 11.
Why do every life process is dependent on other life process?
Answer:
Every life process is dependent on other life process to keep the body in good condition.

Question 12.
Which life process generally maintain the level of different substances in the blood?
Answer:
The life process that maintain the level of different substances in the blood is digestive system.

Question 13.
When do we feel hunger pangs in stomach?
Answer:
When the level of glucose in the blood falls we feel hunger pangs in stomach.

Question 14.
Which hormone is responsible for hunger pangs in stomach?
Answer:
Ghrelin hormone is responsible for hunger pangs in stomach.

Question 15.
The hormone ghrelin is secreted by?
Answer:
The hormone ghrelin is secreted by certain cells in the wall of the stomach.

Question 16.
Which one plays an important role in carrying hunger signals to brain?
Answer:
The diencephalon in fore brain and vagus nerve which is 10th cranial nerve plays an important role in carrying hunger pangs.

Question 17.
How much time does the hunger pangs continue?
Answer:
The hunger pangs continue up to 30 to 45 minutes.

Question 18.
Increase in ghrelin levels results in?
Answer:
Increase in ghrelin levels results in sensation of hunger and motivation to consume food.

Question 19.
Which hormone suppresses hunger?
Answer:
Hormone leptin suppresses hunger.

Question 20.
Which senses enhance our perceptions of the food we eat?
Answer:
Interactions between the senses of taste and smell enhance our perceptions of the food we eat.

Question 21.
What are the different types of papillae present on the tongue?
Answer:
The different types of papillae present on the tongue are filiform papillae, fungiform papillae, foliate papillae and circumvallate papillae.

Question 22.
When do you identify the taste easily?
Answer:
Taste can be identified easily by me when the tongue is pressed against the pallate.

Question 23.
Who conducted experiments on conditioned reflexes?
Answer:
Russian scientist Ivan Pavlov has conducted experiments on conditioned reflexes and found that even the thought of food will water our mouth.

Question 24.
Name the different sets of teeth present in your mouth.
Answer:
The different sets of teeth present in human beings is incisors, canines, premolars and molars.

Question 25.
Write the number of different sets of teeth in human Beings.
Answer:
The number of different sets of teeth in human beings are incisors – 8, canines – 4, premolars – 8, molars -12.

Question 26.
What is mastication?
Answer:
Grinding, chewing and shredding of food in the mouth by teeth is called mastication.

Question 27.
Which cranial nerve controls the movement of a muscle in the jaw?
Answer:
The fifth cranial nerve (Trigeminal nerve) controls the movement of muscles in the jaw.

Question 28.
What is bolus?
Answer:
Food that is formed due to the mastication in the mouth is called bolus.

Question 29.
What is the function of salivary amylase?
Answer:
The enzyme salivary amylase in the saliva breaks down the large starch molecules into smaller subunits usually into sugars.

Question 30.
The controlling center for swallowing food is present in?
Answer:
The controlling center for swallowing food is present somewhere in the brain stem „ (medulla oblongata and others).

Question 31.
Which medium aids in action of enzyme, salivary amylase?
Answer:
Alkaline medium aids in action of enzyme, salivary amylase.

Question 32.
The pH value of alkaline medium is?
Answer:
The pH value of alkaline medium is above 7.

Question 33.
The pH value of acidic medium is?
Answer:
The pH value of acidic medium is below 7.

Question 34.
What are nocturnal animals? Give some examples.
Answer:
The animals which are active during nights are called Nocturnal animals.
Ex: Cockroach, rodents, bats etc.

Question 35.
The amount of saliva secreted by human beings per day is?
Answer:
The amount of saliva secreted by human beings per day is 1 to 1.5 liters.

Question 36.
What kind of tube is oesophagus?
Answer:
Oesophagus is muscular and elastic tube.

Question 37.
How does mucus help in passage of food?
Answer:
Mucus lubricates, protects the walls from damage and helps bolus slide down easily to stomach.

Question 38.
What are the two kinds of smooth muscles present in oesophagus?
Answer:
The two kinds of smooth muscles present in oesophagus are the inner layer consists of circular muscles and the outer layer of longitudinal muscles.

Question 39.
What is peristalsis?
Answer:
The involuntary contraction and relaxation of the muscles of oesophagus, stomach and intestine bring in a wave like motion called peristalsis.

Question 40.
APiich nervous system controls the peristalsis?
Answer:
The involuntary movements peristalsis is under the control of autonomous nervous system.

Question 41.
Which juice is secreted by the wall of stomach?
Answer:
The juice secreted by the wall of stomach is gastric juice which contains hydrochloric acid, mucus and enzyme pepsin.

Question 42.
What is chyme?
Answer:
The digestive juices turns the food into a smooth substance known as chyme. It is the partially digested food in the stomach.

Question 43.
Rumination in cow is the result of?
Answer:
Rumination in cow is the result of reverse peristalsis.

Question 44.
What is the use of reverse peristalsis in human beings?
Answer:
The use of reverse peristalsis in human beings helps in vomiting, (expelling unwanted substances from the food canal.)

Question 45.
How much time does it takes to emptying the food from stomach?
Answer:
Emptying of food from stomach takes nearly 4 to 5 hours.

Question 46.
What causes the stomach to churn and mix the food?
Answer:
Peristalsis causes the stomach to churn and mix the food.

Question 47.
What issthe location of pyloric sphincter? What is its function?
Answer:
Pyloric sphincter present at the opening of stomach and the first part of the small intestine. It releases small quantity of food into the duodenum.

Question 48.
Why should only a small quantity of food be passed from stomach to duodenum?
Answer:
For the complete digestion of the food only a small quantity of food be passed from stomach to duodenum.

Question 49.
What is the nature of the chyme?
Answer:
The nature of the chyme is acidic.

Question 50.
Which hormones in small intestine produced due to the Acidic nature of chyme?
Answer:
Acidic nature of chyme initiates the production of hormones like secretin and cholecystokinin in small intestine.

Question 51.
Secretin and cholecystokinin stimulates the production of?
Answer:
Secretin and cholecystokinin stimulates the production of pancreatic juice, bile juice and succus entericus from pancreas, liver and walls of intestine respectively.

Question 52.
Which process is involved in absorption of nutrients from food?
Answer:
Selective absorption is involved in absorbing nutrients from food.

Question 53.
Which absorb nutrients from the food in small intestine?
Answer:
Finger-like projections called villi absorb nutrients from the food in small intestine.

Question 54.
Anyone with severe cough and cold cannot make out the difference in tastes of certain food items, when the sense of smell is impaired. Why?
Answer:

1. The flavour of food is produced with the combination of taste and smell.
2. The taste or food odour is not individually detected.
3. The interactions between the senses of taste and smell enhance our perceptions of the food.

Question 55.
Seventy percent of our immune system is aimed at?
Answer:
Seventy percent of our immune system is aimed at the gut (elementary canal) to expel and kill foreign invaders.

Question 56.
What is the second brain?
Answer:
The entric nervous system present below the gut or alimentary canal which controls digestion is called second brain.

Question 57.
What is the other name for second brain?
Answer:
The other name for second brain is enteric nervous system.

Question 58.
What is the length of gut or alimentary canal?
Answer:
The length of gut or alimentary canal in man measures about nine meters.

Question 59.
Which part or muscle controls the exit of stool from the body?
Answer:
Anal sphincter controls the exit of stool from the body.

Question 60.
What happens during inhalation?
Answer:
During inhalation oxygen moves across the walls of the alveoli and enters the blood.

Question 61.
What happens during exhalation?
Answer:
During exhalation, carbon dioxide from the blood moves into the alveoli of the lungs and breathed out.

Question 62.
What would be the path of salt removal from gut to the outside of our body?
Answer:
Salt is removed via blood through the kidneys, skin from our body.

Question 63.
Respiration in human beings is controlled by?
Answer:
Respiration in human beings is controlled by medulla oblongata of the autonomous nervous system.

Question 64.
For oxidation of food and transport of substance which processes are to be coordinated?
Answer:
Respiration and blood circulations are to be coordinated for oxidation of food and transport of substances.

10th Class Biology 7th Lesson Coordination in Life Processes 2 Marks Important Questions and Answers

Question 1.
The mere smell or sight of food stimulates hunger. Describe the process in a flow chart.
Answer:

Question 2.
What happens if salivary ducts are closed?
Answer:

1. Salivary glands secrete saliva. Saliva contains mucin and ptyalin or salivary amylase.
2. Mucin gives lubrication to the bolus so that we can easily swallow the food.
3. Ptyalin or salivary amylase digest the complex carbohydrates into simple sugars.
4. If salivary ducts are closed the above processess don’t occur. So that food is not digested properly.

Question 3.
“It is believed that the Diencephalon in fore-brain and vagus nerve (10th cranial nerve) plays an important role in carrying hunger signals to the brain. Hunger pangs continue upto 30-45 minutes. Increase in ghrelin levels results in sensation of hunger and motivation to consume minutes. Increase in ghrelin levels results in sensation of hunger and motivation to consume food.
Read above content and prepare any two questions.
Answer:

1. What are the nerves involved in carrying hunger signals?
2. How long hunger pangs continue?
3. Which part of the brain is the centre for hunger pangs?
4. Which chemical substance is responsible for motivating to consume food?
5. What are the hormones related to hunger?

Question 4.
What will happen, if the small intestine is not like a long coiled tube?
Answer:

1. If size and shape of small intestine is like oesophagus the height of the person should be more than 22 feet as the length of the small intestine is about 22 feet. So it will not fit in the human body.
2. Food will not be digested completely.
3. Digested food will not be absorbed effectively.
4. The food taken into the body is expelled out only after completing partial digestion in stomach.
5. The body suffers from starvation of nutrients.

Question 5.
What did you observe in acid and leaf experiment ? What did you have understand regarding human digestive system from this? (OR)
Take two similar green leaves. Apply grease on one leaf and leave the other free. Add 1 or 2 drops of acid on each leaf. What kind of change do you observe from this?
Answer:

1. The leaf to which grease is applied is not effected with the acid.
2. The leaf to which grease is not applied is effected.
3. From the above activity we can conclude that mucus secreted by the walls of stomach protect it from the harmful effects of hydrochloric acid in the stomach.

Question 6.
Identify the diagram and write two functions of it.
Answer:
This diagram is Liver.
Liver – Functions:

1. Breakdown of larger fats into small globules/emulsification of fats.
2. It excretes Bile salts, cholesterol steroid, hormones, extra drugs, vitamins and alkaline salts through urine.

Question 7.
What will happen if Islets of langerhans fail to function?
Answer:

1. Insulin may not be produced.
2. Human may suffer from sugar/diabetes.
3. Sugar level increases in blood.

Question 8.
What may happen if villi are absent in small intestine?
Answer:

1. Villi increase the surface area of the small intestine for absorption when food passes through it. If villi are absent, food will not be digested completely.
2. Digested food will not be absorbed effectively.
3. The food taken into the body is expelled out only after completing partial absorption in the small intestine.
4. The body will suffer from starvation of nutrients.

Question 9.
Draw the diagram showing peristaltic movement. Write the names of the parts responsible for it.
Answer:
a) Mucus lubricates and protects the walls of oesophagus.
b) Circular muscles and longitudinal muscles of oesophagus help in the movement of food ‘bolus’.
c) Peristalsis is under the control of Autonomous nervous system.

Question 10.
How do we know the taste of the food material? (OR)
What helps us in tasting food material?
Answer:

1. On the tongue different types of papillae are present to sense different tastes.
2. If we want to taste the food material, the food should be dissolved in saliva.
3. We can taste the food that is in the form of liquid only.
4. Only after the dissolved food enters into the cup like taste buds (papillae), the sense of taste is carried to the brain for analysis.
5. Then only we will know the taste of the food material.

Question 11.
Write a short note on digestion of food in mouth.
(OR)
How food is digested in the mouth?
Answer:

1. Saliva is secreted by the action of autonomous nervous system in the mouth.
2. Saliva moistens the food to make chewing and swallowing easier.
3. Due to the mastication of food in the mouth it forms a slurry mass called bolus.
4. The enzyme salivary amylase in the saliva breaks down the large starch molecules into smaller subunits usually into sugars of maltose and dextrose.
5. It is easier and convenient to swallow food after mastication in the mouth.

Question 12.
Why do we salivate during a nap of daytime?
Answer:

1. We are diurnal animals, we are active during daytime and take rest at night.
2. Ail the systems of our body are active in function during the daytime of our activity. Hence, man is a diurnal animal.
3. Our digestive system is also active and ready to receive the food for digestion.
4. If we sleep during daytime saliva oozes out of our mouth and wets the pillows.
5. This will not happen during night time.

Question 13.
Write a brief account on travel of food through oesophagus.
(OR)
How food travels in the oesophagus?
Answer:

1. Oesophagus is a tube like structure.
2. the wall of the oesophagus is made up of two kinds of smooth muscles.
3. The inner layer consisting of circular muscles and the outer layer with longitudinal muscles.
4. Contraction of the circular muscles results in narrowing of the oesophagus just behind the bolus. So the food is squeezed downwards.
5. Contraction of the longitudinal muscles in front of the bolus widen the tube, this results in shortening of that particular part of the oesophagus.
6. Contraction and relaxation of these muscles bring in a wave like motion that propels the food bolus into the stomach by ‘peristalsis’.

Question 14.
The digestive tract is unique among internal organs. Write few lines by supporting this statement.
Answer:

1. The digestive tract is unique among internal organs because it is exposed to a large variety of physio chemical stimuli from the external world in the form of ingested food.
2. As a consequence, the intestine has developed a rich store of coordinated movements of its muscular apparatus along with neural apparatus to ensure the appropriate mixing and propulsion of contents during digestion, absorption and excretion.
3. The neural apparatus of our digestive tract comprises of such a vast and complicated network of neurons that it has been nicknamed by scientists as the second brain.

Question 15.
How taste is identified by us? (OR) How can we identify taste?
Answer:

1. Any food substance when placed on the tongue gets dissolved in the saliva secreted by salivary glands in the mouth.
2. When the tongue is pressed against the palate the food substance is pressed against the opening of the taste bud letting it to reach the taste cells and triggering taste signals.
3. Finally the taste is recognized in the brain.

10th Class Biology 7th Lesson Coordination in Life Processes 4 Marks Important Questions and Answers

Question 1.
Give reasons:
A) Hunger generating signals reach the brain when stomach gets empty.
Answer:
Ghrelin is secreted from walls of the stomach.
B) When your stomach is filled with full of food, you feel you don’t need food any more.
Answer:
Leptin Hormone is secreted which suppresses hunger.
C) In severe cold and cough, one cannot feel the taste of the food.
Answer:
During cold olfactory receptors are blocked.
D) We cannot identify the taste of a grape fruit, when it is placed on the tongue.
Answer:
We cannot taste the grapes because it is not in the liquid state.

Question 2.
A) What is the function of peristalsis in these parts of Human digestive system?
a) Oesophagus
b) Stomach
c) Small intestine
d) Large intestine
Answer:
a) Oesophagus: Bolus moves towards the stomach.
b) Stomach : Peristalsis helps in storing food, breaking down food, mixing the food with gastric juice.
c) Small intestine : Peristalsis helps in mixing the chyme with digestive juices.
d) Large intestine: Peristalsis helps to propel undigested material into rectum.

Question 3.
Observe the following schematic diagram and answer the following questions:

i) What do you call the wave like movements shown by the muscles of Oesophagus?
Answer:
Peristalsis.

ii) What is the structure of Oesophagus?
Answer:
Long tube like structure.

iii) How does mucus help in passage of food?
Answer:
Mucus helps the food to slide down easily.

iv) Which parts of alimentary canal are connected by the Oesophagus?
Answer:
Pharynx and stomach.

Question 4.
What is peristaltic movement? Compare the similarity of bolus movement in oesophagus with cycle tube and potato experiment which you have conducted in school.
Answer:
Peristalsis: Contraction and relaxation of circular and longitudinal muscles bring in a wave – like motion that propels the food bolus into the stomach from oesophagus by the action called as peristalsis.
Experiment:
Aim: Making a model of oesophagus to observe how bolus moves forward.
Material required: Potatoes, cycle tube lubricate oil.
Procedure:

1. Take a piece of waste cycle tube and insert one or two potatoes into it.
2. Lubricate the inner side of the tube with oil.
3. In the same way smear oil over potatoes.
4. Insert oil coated potatoes in the tube. Potatoes in cycle tube
5. Now try to push the potatoes by squeezing the tube from behind the potato.

Observation: Oil acted as lubricant to push the potato easily in the forward direction. Conclusion: The muscles in the wall of the oesophagus have bring in a wave like movement due to contraction and relaxation, that propels the food bolus into the stomach.
This action is called as peristalsis.

Question 5.
Write the procedure involved in the acid and leaf experiment to understand the concept “how the stomach gets protected from its own acid secretions”. Compare the observations with the changes that takes place in human digestive system.
Answer:

1. Take two similar green leaves.
2. Grease one leaf with petroleum jelly, leave the other free.
3. Add 1 or 2 drops of some weak acids on both the leaves.
4. Observe them after half-an-hour or so and write your observations.
5. The leaf to which petroleum jelly was not applied effected by the acid.
6. We observe the colour of the leaf changes.
7. The other leaf was not affected by the acid because of petroleum jelly.
   From the above activity we can conclude that mucus secreted by the walls of stomach protects the stomach it from the harmful effects of hydrochloric acid.

Question 6.
Vasu is doing experiment, lab activities in his classroom. He is tired due to hungry. How hungry feeling occurs? How will one know?
Answer:

1. Levels of different substances are generally maintained in the blood mainly by our digestive system.
2. One of the major substance is glucose.
3. When its levels in the blood fall, we get hunger pangs in stomach.
4. Ghrelin is secreted from the certain cells in the wall of the stomach.
5. Hunger contractions (hunger pangs) start to occur in the stomach due to the secretion of Ghrelin hormone.
6. Increase in ghrelin levels results in sensation of hunger and motivation to consume

Question 7.
What is peristaltic movement? Explain the food movement in alimentary canal comparing with the experiment of moving potatoes in cycle tube.
Answer:
Peristaltic movement is the contraction and relaxation of the muscles of the digestive system. The movement of food through food pipe is known as peristaltic movement.
Food movement in alimentary canal:

1. The walls of the food pipe secrete a slippery substance called mucus. Mucus lubricates and protects the oesophageal walls from damage.
2. This helps the food bolus to slide down easily just as the oiled potatoes that move in the tube. Oil acts as lubricant and push the potatoes easily in the forward direction.
3. The wall of the oesophagus is made up of two kinds of smooth muscles. The inner layer consists of circular muscles and the outer layer of longitudinal muscles.
4. Contraction of the circular muscles results in narrowing of the oesophagus just behind the bolus.
5. So the food is squeezed downwards.
6. Contraction of the longitudinal muscles in front of the bolus widen the tube, this results in shortening of that particular part of the oesophagus.
7. Contraction and relaxation of these muscles bring in wave like motion that propels the food bolus into the stomach by the action called as peristalsis.
8. This is involuntary and under the control of autonomous nervous system.

Question 8.
Write briefly about the functional and structural aspects of oesophagus in human beings.
Answer:

1. Oesophagus is a long muscular and elastic tube-like part of the digestive system which lies between pharynx and stomach.
   
2. The wall of the oesophagus is made up of two kinds of smooth muscles.
3. The inner layer consists of circular muscles and the outer layer of longitudinal muscles.
4. The walls of the oesophagus secrete mucus, a slimy substance which helps in the easy movement of food into the stomach.
5. Walls of oesophagus carry on wave-like movement by contraction and relaxation. These movements are known as peristalsis.
6. Due to the peristalsis movements food passes from oesophagus into stomach.

Question 9.
Explain briefly about the structure of stomach. (OR)
What is the role of stomach in digestion of food ?
Answer:

1. Our stomach is not a bag with specific volume. It is a like a pouch which is elastic in nature.
2. The size of the stomach increases based on the food we intake.
3. Digestive juices are produced depending on the quantity of food material.
4. The walls of the stomach secrete juice containing hydrochloric acid.
5. Mucus secreted by some cells in the walls of the stomach form a thin lining on the walls of the stomach. This counters the action of acid.
6. The food is thoroughly mixed with the digestive juices by peristaltic movements of muscles in stomach.
7. The digestive juices of the stomach turns food into a smooth liquid mass called chyme.

Question 10.
Draw peristaltic movement of food in stomach. Describe movement of food in stomach.
Answer:

1. The stomach acts like a washing machine, churning the food around to break it into even smaller pieces.
   
2. Mechanical mixing of food in stomach occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall.
3. The contractions of the stomach muscles squeeze and mix the food with the acids and juices of the stomach.
4. The digestive juices turns the food into smooth paste like substance called chyme.
5. As the process of digestion in the stomach nears completion, the contractions of the stomach decrease.

Question 11.
Describe with diagram how villi are helpful in absorption of digested food in small intestine.
(OR)
How digested food is absorbed in small intestine?
Answer:

1. The small intestine is the main region for the absorption of digested food.
2. The inner surface of the small intestine contains thousands of finger like projections called Villi.
   
3. These villi increase the surface area;so that the food retained in the folds can remain longer thereby enhancing absorption.
4. Blood vessels and lymph vessels are present in the form of a network in the villi.
5. Products of digestion are absorbed first into the villi and from there into the blood vessels and lymph vessels.

Question 12.
Write about the experiment conducted by Ivan Pavlov on conditioned reflex.
Answer:

1. Ivan Pavlov was a Russian scientist conducted experiments on conditioned reflexes.
2. He discovered that dogs produced extra saliva when they were offered food.
   
3. Pavlov noticed, that they also did the same when the person who fed them came into the room, even if the person had not brought any food.
4. Pavlov went on to ring a bell at the start of feeding time, and eventually the dogs produced extra saliva when they heard the bell, before any food was brought.
5. A dog salivating when it hears a bell is not a natural response.
6. They would not do this without being conditioned to do so.
7. The behaviour has been learned. It is called a conditioned response.

Question 13.
Explain the process of exit of waste materials from large intestine.
Answer:

1. When the unwanted waste material reach the large intestine, the peristaltic waves move the stool into the rectum.
2. Water gets reabsorbed and the remaining waste usually hard mass that gets stored in the last part of the large intestine i.e., rectum.
   
3. There are two muscular layers helping the exit of stools.
4. One that is under involuntary control and the other is under voluntary control.
5. The muscular structures helps in opening and closing of the aperture of a canal is called sphincter.
6. Anal sphincter controls the process of exit of waste materials from large intestine.

AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 9 Our Environment.

AP State Syllabus SSC 10th Class Biology Important Questions 9th Lesson Our Environment

10th Class Biology 9th Lesson Our Environment 1 Mark Important Questions and Answers

Question 1.
Suggest one alternative method in place of pesticides to protect crops?
Answer:
Alternative methods for using pesticides to save the crops from pests:

1. Rotation of crops
2. Studying the life histories of pests
3. Biological Control
4. Sterility
5. Genetic Strains

Question 2.
By taking two plants of your surroundings as examples, explain how they protect themselves against the animals which eat them.
Answer:

1. Neem Tree: Neem leaves contain an alkaloid Nimbin to protect themselves from the animals which eat them.
2. Cactus: They have thorns to protect themselves.
3. Datura: Datura leaves gives bad odour.

Question 3.
Identify one food chain from your surroundings. Name the producers and different levels of consumers in that food Chain.
Answer:
Grass → Insects → Frog → Snake.
Producers – Grass.
Primary Consumers – Insects.
Secondary Consumers – Frog
Tertiary consumers – Snake.

Aquatic Plants → Insects → Fish → Crane.
Producers – Aquatic Plant.
Primary Consumers – Insects
Secondary Consumers – Fish
Tertiary consumers – Crane

Question 4.
Write the names of producers and consumers in the food chain, you have observed.
Answer:
Producers – Plants, Green Algae
Consumers – All Animals.

Question 5.
Write any two slogans to promote awareness among the people about Ecofriendly programs.
Answer:
a) Lets go green to get global clean.
b) If you disturb the nature, the nature will disturb you.
c) The best solution to arrest pollution is plantation.
d) Reduce the usage of plastic and reduce the pollution.

Question 6.
What happens if decomposers are removed from the food web?
Answer:

1. If decomposers are removed from the food web then the biological cycles are not completed.
2. If the decomposers are not present in an ecosystem the remains of the other organisms accumulate.

Question 7.
Observe the following given below. Draw the pyramid of numbers.
Grass → Goat → Man
Answer:

Question 8.
We can’t expect the world without sparrows. So how should be our concern towards their conservation?
Answer:

1. Sparrows are useful to control harmful insects like locust which damage food grains.
2. Chemical pesticides are the cause for destruction of sparrows and useful insects.
3. By using biological methods we can conserve the sparrow population.

Question 9.
Human being is modifying agriculture lands and lakes into residential areas. What is its effect on Bio-diversity?
Answer:

1. The shelter may not be provided for migratory birds.
2. Food chain get disturbed.
3. Decrease in the ground water level.

Question 10.
How do you protect the plants, which were planted in “Haritha Haaram” programme in your school?
Answer:
We protect the plants:

1. Watering of plants at regular intervals.
2. Fencing or gaurding of plants.
3. Adoption of plants.
4. Providing organic manure.

Question 11.
The figure given below represents a food pyramid. Study it and answer the following questions.

i) Which trophic level has maximum energy?
Answer:
T₁ (or) Primary producers (green plants)
ii) Give one example for T₄ trophic level.
Answer:
Lion, tiger, hawk, etc.

Question 12.
“We can’t imagine the world without insects and birds, conserve them.
Answer:
Methods to conserve insects and birds:

1. Avoid indiscriminate usage of pesticides
2. Protect the natural habitats of insects and birds.
3. Development of bird sanctuaries
4. Everyone should follow environmental ethics.

Question 13.
What is environment?
Answer:
The sum of physical and biological factors along with their chemical interactions that affect an organism is called environment.

Question 14.
What is biosphere?
Answer:
The world of living things is called biosphere.
(OR)
The life supporting zone on the earth is called biosphere.

Question 15.
What are the physical or abiotic factors in a biosphere?
Answer:
Land, air, water, sunlight, humidity etc. are the physical or abiotic factors in a biosphere.

Question 16.
What does a food chain show?
Answer:
Food chain shows that how the energy is passed from one organism to another.

Question 17.
How the terrestrial ecosystems are determined?
Answer:
The terrestrial ecosystems are determined largely by the variations in climatic conditions between the poles and equator.

Question 18.
Where did the Kilimanjaro mountain located?
Answer:
The Kilimanjaro mountain is located in equatorial Africa (present in Tanzania, Africa).

Question 19.
What is the main source of energy for all the organisms in an ecosystem?
Answer:
Sunlight is the main source of energy for all the organisms in an ecosystem.

Question 20.
What is food web?
Answer:
The network of a large number of food chains existing in an ecosystem is called a food web.

Question 21.
What does a food web indicate?
Answer:
A food web indicates that the number of possible links for food in an ecosystem and reflects the fact that the whole community is a complex inter-connected unit.

Question 22.
What is ‘niche’?
Answer:
The position of organisms in a food web.

Question 23.
What does the word ‘niche’ denotes?
Answer:
‘Niche’ is the term used to describe not only the animals position in the food web and what it eats but also its mode of life.

Question 24.
What is an ecological pyramid?
Answer:
The graphic representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called “Ecological pyramid”.

Question 25.
Who was the first one to introduce “Ecological pyramid”?
Answer:
Ecological pyramid was first introduced by a British Ecologist Charles Elton in 1927.

Question 26.
In ecological pyramids the producers are represented at?
Answer:
The producers are represented at the base of the ecological pyramids.

Question 27.
What is pyramid of number?
Answer:
A graphical representation designed to show the number of organisms at each tropic level in a given ecosystem is called “pyramid of number”.

Question 28.
What does the pyramid of number show?
Answer:
Pyramid of number shows the population of organisms at each tropic level in a food chain.

Question 29.
What does each bar represent in a pyramid of number?
Answer:
In a pyramid of number, each bar represents the number of individuals at each tropic level in a food chain.

Question 30.
When does the pyramid of number not look like a pyramid at all?
Answer:
If the producer is a large plant such as tree or if one of the organisms at any tropic level is very small, then the pyramid of number does not look like a pyramid.

Question 31.
What is biomass?
Answer:
Any type of plant or animal material that can be converted into energy is called biomass.

Question 32.
What is biofuels?
Answer:
The materials which are used for energy production are known as biofuels.

Question 33.
What is Pyramid of biomass?
Answer:
A graphical representation designed to show the quantity of living matter at each tropic level in a given ecosystem is called “Pyramid of biomass”.

Question 34.
Why Pyramid of biomass inverted in case of aquatic ecosystem?
Answer:

1. In an aquatic ecosystem, the biomass of phytoplankton is quite negligible as compared to that of the crustaceans and small herbivorous fish that feed on these producers.
2. The biomass of large carnivorous fish living on small fishes is still greater. This makes the pyramid of biomass inverted.

Question 35.
How much percentage of the biomass is transferred from one tropic level to the next in a food chain?
Answer:
The percentage of the biomass transferred from one tropic level to the next level in food chain is nearly 10 – 20%.

Question 36.
When does the species at the top of the pyramid get more energy?
Answer:
The species at the top of the pyramid get, more energy when the steps in a food chain are fewer.

Question 37.
What are bio-geochemical cycles?
Answer:
Flow of materials between organisms and their environment is called cycling of materials or bio-geochemical cycles.

Question 38.
What is ecological efficiency?
Answer:
The ratio between energy flows at different tropic levels among the food chain expressed as percentage is called ecological efficiency.

Question 39.
What is ten per cent law?
Answer:
During the transfer of energy from one tropic level to the next, only about ten per cent of the energy from organic matter is stored as flesh. This is called “Ten per cent law”.

Question 40.
Where do Kolleru one of the largest fresh water lakes in India exists?
Answer:
Kolleru is one of the largest fresh water lakes in India exists between West Godavari and Krishna districts of Andhra Pradesh.

Question 41.
What is the catchment area of the lake Kolleru?
Answer:
A catchment area of the Kolleru lake extends up to 6121 Km2.

Question 42.
Through which The lake Kolleru discharges its excess water into Bay of Bengal?
Answer:
The lake Kolleru discharges its excess water into Bay of Bengal through the twisty channel called Upputeru which is about 65 km long.

Question 43.
When did Government of Andhra Pradesh had declared the lake as Bird Sanctuary?
Answer:
In November 1999, Government of Andhra Pradesh had declared the lake as Bird Sanctuary.

Question 44.
What is the number of species of birds being hosted by the Kolleru?
Answer:
The Kolleru lake is hosting 193 species of birds.

Question 45.
What are the major sources of pollution in Kolleru lake?
Answer:
The major sources of pollution are agricultural runoff containing residues of several agrochemicals, fertilizers, fish tank discharges, industrial effluents containing chemical residues and different types of organic substances, municipal and domestic sewage.

Question 46.
What is the objective of “Operation Kolleru” by the ministry of environment and forest, Government of India?
Answer:
The objective of operation Kolleru by the ministry of environment and forest, Government of India is to bring back the ecological balance of Kolleru lake which is a gift of nature.

Question 47.
What is Bioaccumulation?
Answer:
The process of entering of pollutants in a food chain is known as Bioaccumulation.

Question 48.
What is Biomagnification?
Answer:
The tendency of pollutants to concentrate as they move from one tropic level to the next is known as Biomagnification.

Question 49.
What are pesticides?
Answer:
The chemical materials used to control pests that attack crop plants or live as parasites on the body of farm animals are called pesticides.

Question 50.
What is a perfect pesticide?
Answer:
The perfect pesticide is one which destroys a particular pest and is completely harmless to every other form of life.

Question 51.
Why did the egg breaking among the peregrines increase?
Answer:
Egg breaking among the peregrines increased due to their disturbed behaviour caused by the nerve poisons that entered into their tissues through food chain.

Question 52.
Why did the aquatic biota is being contaminated?
Answer:
The aquatic biota is being contaminated with heavy metals due to industrialization and anthropogenic activities.

Question 53.
Why fish are considered to be the bioindicators of metal contamination?
Answer:
Fish are considered to be the bioindicators of metal contamination in environmental monitoring because fish species are strongly respond to stress conditions.

Question 54.
Where did Edulabad water reservoir located?
Answer:
Edulabad water reservoir is located in urban areas of Ranga Reddy district of Telangana.

Question 55.
Which fish species is grown in Edulabad water reservoir?
Answer:
Cyprinus carpio (common scale carp) is the fish species grown in Edulabad water reservoir.

Question 56.
What are the effects of bioaccumulation of metals in human beings that eat cyprinus carpio?
Answer:
The bioaccumulation of various metals in cyprinus carpio cause disorders. Such as hypertensions, sporadic fever, renal damage, nausea, etc.

Question 57.
In which country sparrows were hunted extensively in 1958?
Answer:
In China sparrows were hunted extensively in 1958.

Question 58.
In your opinion what are the effective methods to control pests?
Answer:
Rotation of crops, biological control, developing genetically modified plants are the effective methods to control pests in my opinon.

Question 59.
Why the temperatures are very high during the day and cold during the nights in deserts?
Answer:
In deserts, the rainfall and humidity are very low, so the sun’s rays easily penetrate the atmosphere making ground temperatures very high during the day. But the nights are often cold as the earth loses heat rapidly.

Question 60.
How can we draw a food chain?
Answer:
We can draw a food chain by connecting the pictures or names of organisms by putting arrows between them. These arrows should always point from food to the feeder.

Question 61.
How many types of ecological pyramids are there in practice? Name them.
Answer:
There are three types of ecological pyramids. They are:

1. Pyramid of number
2. Pyramid of biomass and
3. Pyramid of energy.

Question 62.
Which process helps to convert the solar energy into suitable form of energy for animals to consume?
Answer:
Photosynthesis helps to convert the solar energy into suitable form of energy (food) for animals to consume.

10th Class Biology 9th Lesson Our Environment 2 Marks Important Questions and Answers

Question 1.
Grass → Grasshopper → Frog → Snake → Hawk
What will happen if we remove Frog from the above food chain? Explain.
Answer:

1. Frog is secondary consumer in this food chain.
2. If we remove frog from the food chain, the number of grasshopper will increase on other hand the number of snakes which depend on frogs will decrease.
3. Hence, ecological balance may be damaged.

Question 2.
Observe the diagram and answer the following.
i) Write any two food chains from the diagram.
ii) What are the secondary consumers in the food chain that are written by you?
Answer:
i) a) Plants → Goat → Tiger
b) Plants → Rabbit → Wolf / Fox
ii) Tiger, Wolf / Fox

Question 3.
Study the given paragraph and answer the questions.

Solar energy from sun enters into the producers of an ecosystem. No organisms except green plants and photosynthetic bacteria can absorb solar energy and convert it into chemical energy.

A) What are the producers mentioned in the given paragraph?
B) What form is energy converted into photosynthesis? In Photosynthesis, which form is energy converted into?
Answer:
A) Green plants and photosynthetic bacteria.
B) In photosynthesis, the light (or) solar energy is converted into chemical energy.

Question 4.
Explain the flow chart given below.
Answer:
It is the pyramid of biomass.

1. In this pyramid 10% of the food will reach to the next trophical level and so on at each level.
2. It would take 1000 kg of phytoplankton to provide 100 kg of zooplankton and to form 1 kg of human tissue, 10 kg of frog is needed.
3. The fewer the steps in the food chain, the more energy will be for the species at the top.

Question 5.
Observe the pyramid of number which is given below and answer the questions.
i) As per the number of organisms in the tropic level, which group of organisms
are more in number and which are less in number?
ii) What happens if Secondary consumers disappear?
Answer:
i) If producers are more in number, then tertiary consumers are less in number,
ii) If secondary consumers disappear the primary consumers increase in number and the tertiary consumers found no food to live. It leads to death.

Question 6.
Explain in brief about the alternate methods to be followed to prevent the harmful effects of over usage of pesticides.
(OR)
Mention any four effective methods of controlling pests, which are less harmful on environment based on biological principles.
Answer:
Some of alternative pest control methods are

1. Rotation of Crop: Growing different crops on a particular piece of land in successive years.
2. Studying the life histories of the pests: When this is done it is sometimes possible to sow the crops at a time when least damage will be caused.
3. Biological Control: Introducing Natural predator or parasite of the pest.
4. Sterility: Rendering the males of a pest species sterile.
5. Genetic Strains: The development of genetic strains (genetically modified plants) which are resistant to certain pest.
6. Environmental ethics: People need to know besides laws regarding environment there are some basic ethics what is right and what is wrong in view of environment.

Question 7.
Write any 4 slogans on the necessity of forests and on their conservation.
Answer:

1. Save the trees, save the earth. We are the guardians of nature’s birth.
2. Don’t destroy the greenary and don’t spoil the scenery.
3. Don’t make trees rare, we should keep them with care.
4. To live for future in rest, saving forest is the best.

Question 8.
How does the given below concepts differs?
(a) Bioaccumulation b) Biomagnification
Answer:
a) Bioaccumulation: The process of entry of pollutants into a food chain is known as bioaccumulation.
b) Biomagnification: It is the tendency of pollutants to concentrate as they move from one tropic level to the next is known as biomagnification.

Question 9.
The biomass of a producer in an ecosystem is calculated as 3500 kgs. Calculate the biomass of primary, secondary, tertiary consumers.
Answer:
In a food chain roughly 90% of the food is lost at each step. So if the biomass of a producer in an ecosystem is calculated as 3500 kgs. the biomass of primary consumer as will be 350 kgs. and of secondary consumer is 35 kgs and biomass of tertiary consumer is 3.5 kgs.

Question 10.
Write a short note on food chain and food web.
Answer:

1. Food chain is a pathway along which food is transferred from one tropic level to another tropic level beginning with producers.
2. It shows who eats what in a particular habitat.
3. The arrows between each item in the chain always point from the food to the feeder.
4. For example
   Grass → Rabbit → Snake → Hawk
5. The elaborate interconnected feeding relationships in an ecosystem is said to be food web.
6. Many of the food chains in an ecosystem are crosslinked to form food web.
7. For example,
   
8. Food chain and food web help us to understand the food relations among living things.

Question 11.
Write a short notes on ecological pyramids.
Answer:

1. The graphical representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called “Ecological pyramid”.
2. It was first introduced by a British Ecologist Charles Elton in 1927.
3. In the ecological pyramid, the producers (First tropic level) are represented at the base, and the successive tropic levels (primary, secondary and tertiary consumers) are represented one above the other with top carnivores at the tip.
4. There are three types of pyramids.
   i) Pyramid of number ii) Pyramid of biomass and iii) Pyramid of energy.
5. Pyramid of number shows the population of organisms at each tropic level in a food chain.
6. Pyramid of biomass represents the available food as a source of energy at each tropic level in the food chain.
7. Pyramid of energy represents the available energy at each tropic level in food chain.

Question 12.
Write a short notes on pyramid of number.
Answer:

1. Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem.
2. The shape of this pyramid varies from eco-system to ecosystem.
   
3. In aquatic and grassland ecosystems, numerous small autotrophs support lesser herbivores which support further small number of carnivores and hence the pyramid structure is upright.
   
4. In forest ecosystem, less number of producers support greater number of herbivores who in turn support a fewer number of carnivores. Hence the pyramid structure is partly upright.
5. In parasitic food chain, one primary producer supports numerous parasites which support still more hyperparasites. Hence the pyramid structure is inverted.
   

Question 13.
Write a short notes on pyramid of biomass.
Answer:

1. Pyramid of biomass is a graphical representation designed to show the quantity of living matter (biomass) at each tropic level in a given ecosystem.
2. In terrestrial ecosystems, the biomass progressively decreases from producers to top carnivores. Hence the pyramid structure is upright.
   
3. In an aquatic ecosystem, the biomass of phytoplankton (producers) is quite negligible as compared to that of crustaceans and small herbivorous fish that feed on these producers. The biomass of large carnivorous fish living on small fishes is still greater. This makes the pyramid of biomass inverted.
   

Question 14.
How do pesticides cause Bioaccumulation and Biomagnification?
(OR)
What are the effects of pesticides on environment?
Answer:

1. Pesticides are the toxic chemicals used to destroy pest and insects which damage our crops and stored foods.
2. These pesticides vary in their length of life as toxic materials.
3. Some of the pesticides are degradable that can be broken down into harmless substances in a comparatively short time and others are non-degradable.
4. Non-degradable pesticides accumulate in the bodies of animal and pass right through food web.
5. Thus the pesticides cause bioaccumulation.
6. These accumulated pesticides concentrate as they move from one tropic level to the next, thus leads to biomagnification.

Question 15.
List out some human activities which altered the communities of plants and animals in their natural ecosystem.
Answer:

1. Industrialization
2. Damming rivers
3. Draining marshes
4. Re-claiming land from the sea
5. Cutting down forests
6. Using chemical fertilisers and pesticides
7. Building towns, cities, canals and motor ways.

Question 16.
What kind of changes may come in 2m ecosystem due to development of a large town?
Answer:
The following changes are expected due to development of a large town.

1. Some plants and animal species will die out.
2. Some will adapt to the new conditions sufficiently to survive in reduced numbers.
3. Some will benefit by the new conditions and will increase in numbers.

Question 17.
Write a comparative note on pyramid of number and pyramid of biomass.
(OR)
Write the differences between pyramid of number and pyramid of biomass.
Answer:

Pyramid of number	Pyramid of biomass
1. Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem.	1. Pyramid of biomass is a graphical representation designed to show the quantity of living matter at each tropic level in a given ecosystem.
2. It shows the population of organisms at each tropic level in a food chain.	2. It represents the available food as a source of energy at each tropic level in the food chain.
3. This pyramid sometimes does not look like a pyramid at all. It may be upright like in grassland ecosystem, partly upright like in forest ecosystem or inverted like in parasitic ecosystem.	3. This pyramid may be upright like in terrestrial ecosystem or inverted like in aquatic ecosystem.

Question 18.
Write a comparative note on pyramid of biomass and pyramid of energy.
(OR)
What are the differences between pyramid of biomass and pyramid of energy?
Answer:

Pyramid of biomass	Pyramid of energy
1. Pyramid of biomass is a graphical representation designed to show the quantity of living matter at each tropic level in a given ecosystem.	1. Pyramid of energy is a graphical representation designed to show the quantity of energy present at each tropic level in a given ecosystem.
2. It represents the available food as a source of energy at each tropic level in the food chain.	2. It represents the available energy at each tropic level in the food chain.
3. This pyramid may be upright like in terrestrial ecosystem or inverted like in aquatic ecosystem.	3. This pyramid is always upright as only 10% of energy from one level is transfering to the next level.

Question 19.
Write a comparative note on pyramid of number and pyramid of energy?
(OR)
What are the differences between pyramid of number and pyramid of energy?
Answer:

Pyramid of number	Pyramid of energy
1. Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem.	1. Pyramid of energy is a graphical representation designed to show the quantity of energy present at each tropic level in a given ecosystem.
2. It shows the population of organisms at each tropic level in a food chain.	2. It shows the available energy at each tropic level in a food chain.
3. This pyramid sometimes does not look like a pyramid at all. It may be upright like in a grassland ecosystem partly upright like in forest ecosystem or inverted like in parasitic ecosystem.	3. This pyramid is always upright, as only 10% of energy is transfering from one tropic level to other.

Question 20.
What is ecological efficiency? Write a short notes on Ten per cent law?
Answer:
Ecological efficiency: The ratio between energy flows at different tropic levels along the food chain expressed as percentage is called “ecological efficiency”.
Ten per cent law:

1. The amount of energy transferred decreases with successive tropic levels.
2. Slobodkin (1959) suggested that the transfer of energy from one tropic level to the next is of the order of 10% and this is called “Gross ecological efficiency”.

Question 21.
Geetha said “a given species may occupy more than one tropic level in the same ecosystem at the same time”. Do you support her or not? Explain your answer with example.
Answer:
I support her for the following reason.

1. A snake eating a mouse in a field or lawn occupies the third tropic level.
   Plant → Mouse → Snake
2. When the snake eats a frog in the same field, it occupies the fourth tropic level in a food chain. It is because the frog feed on some of the insects that depend on the plants.
   Plant → Insect → Frog → Snake
3. Thus, a given species may occupy more than one tropic level in the same ecosystem at the same time.
4. This is to satisfy its food needs, as it cannot do so by occupying one tropic level.

Question 22.
If we introduce a man into a forest ecosystem, at which level of food chain we will place him? Explain your answer.
Answer:

1. If we introduce a man into a forest ecosystem, he can fit for any level of consumers of food chain.
2. He may feed on plant parts such as fruits. Then we can place him at primary consumer level.
   Plant → Man
3. He may feed on some of the herbivorous organisms such as rabbit, then we can place him at secondary consumers level.
   Plant → Rabbit → Man
4. He may also feed on some of the carnivorous organisms such as insectivorous birds then we can place him at tertiary consumers level.
   Plant → Insect → Bird → Man
5. This is possible to place him at any level of consumers, as he is an omnivore, who feed on both plant originated and animal originated foods.

Question 23.
Draw the ecological pyramids for the given food chain.
Banyan Tree → Herbivorous birds → Carnivorous birds.
Answer:
1) Pyramid of number

2) Pyramid of biomass

3) Pyramid of energy

Question 24.
Write briefly about Minamata disease.
Answer:

1. Minamata disease was first discovered in Minamata city in Kumamoto prefecture, Japan, in 1956.
2. It was caused by the release of methyl mercury in the industrial waste water from the Chisso corporation’s chemical factory, which continued from 1932 to 1968.
3. This highly toxic chemical bioaccumulated in shellfish and fish in Minimata Bay and the Shiranui Sea, which, when eaten by the local populace, resulted in mercury poisoning.
4. While cat, dog, pig and humans death continued for 36 years.

Question 25.
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
Answer:

1. Trophic levels is the feeding position in a food chain.
2. It is the functional level occupied by an organism in a food chain.
3. Examples of trophic levels include ‘herbivores’ and ‘decomposers’
4. An example of food chain depicting various trophic levels is as follows:
   

Question 26.
What is the role of decomposers in the ecosystem? (OR)
How decomposers help in cleaning the environment?
Answer:

1. If the decomposers are not present in an ecosystem the remains of the other organisms accumulate.
2. Eventually the world would run out of carbon dioxide or nitrate or phosphate or other inorganisms material essential for life.
3. The decomposers breakdown the organic waste products and dead remains of organisms into the inorganic substances needed by the producers.
4. Most decomposition is carried out by saprophytic fungi, by bacteria and by invertebrates.

10th Class Biology 9th Lesson Our Environment 4 Marks Important Questions and Answers

Question 1.
Prepare some slogans about ‘Vanam – Manam’ programme to display in your school rally?
Answer:

1. Save paper – Save trees
2. Plant a tree – Plant a life
3. Saving trees is our duty
4. Think green – Go green
5. If we protect plants – they protects us
6. Conserve plants – Conserve life
7. Plant a tree – get the air free
8. Plant a tree – Reduce the pollution.
9. Tree on – Global warming gone.
10. If cut a tree – It kills a life.

Question 2.
Read the information about Kolleru lake in the given table and answer the following questions.

Classes	Area in 1967 (Km2)	Area In 2004 (Km2)
Lake-water spread area	70.70	62.65
Lake with sparse weed	0	47.45
Lake with dense weed	0	15.20
Lake-liable to flood in rainy season	100.97	0
Aquaculture ponds	0	99.74
Rice fields	8.40	16.62
Encroachment	0.31	1.37
Total	180.38	180.38

a) In which year, lake water spread area is more?
b) Why do you think weeds are more in the lake?
c) Guess the reasons for decrease in the lake area.
d) What measures are to be taken to control pollution in the lake?
Answer:
a) In the year 1967
b) Addition of excessive nutrients from aquaculture ponds and rice fields.
c) Aquaculture ponds, Ricefields and Encroachment are the reasons for decrease in lake area.
d) Anthropogenic activities are to be controlled in the lake catchment area. (Or)
Fish ponds are to be removed in the lake catchment area. (Or)
Agricultural practices in the lake area should be minimised as per the norms of government.

Question 3.
Observe the following pyramid of biomass and answer the following questions.
a) This pyramid shows a decrease in the biomass as we move up, why the biomass is decreasing?
Answer:
The pyramid of biomass for the given food chain, at each step 90% of the food is lost. That means 1000 kg of phytoplankton to produce 100 kg of Zooplankton to form 10 kg of fish to produce 1kg of human tissues. The fewer the steps in the food chain the more energy will be for the species at the top.

b) Give some examples of producers and primary consumers.
Answer:
Examples for producers: Plants, Grass, Diatoms.
Examples for primary consumers: Grasshopper, Rabbit, Deer,

c) Where do producers get the energy from?
Answer:
From the sun.

d) How much biomass is lost at each step?
Answer:
90%

Question 4.
Observe the following diagram and answer the following questions.
i) Name the primary producers in the given food web.
ii) Prepare any one food – chain from the diagram.
iii) What are the tertiary consumers?
iv) Write names of any two herbivores.
Answer:
i) Plants, Grass, Trees Phytoplanktons etc.
ii) Grass → Rabbit → Fox → Tiger
iii) Tiger, Vulture, Crane, Owl, Peacock etc.
(OR)
The animals which are at 4th trophic level in a food chain are called as Tertiary Consumers.
iv) Rabbit, Deer, Goat, Cow

Question 5.
What is number pyramid? What does it indicate?
Answer:

1. The number of organisms in a food chain can be represented graphically in a pyramid of number.
2. Each bar represents the number of individuals at each tropic level in a food chain.
3. At each link in a food chain, from the first order consumers to the large carnivores, there is normally an increase in size but decrease in number.
4. For example in a wood, the aphids are very small and occur in astronomical numbers.
5. The lady birds which feed on them are distinctly larger and not so numerous.
6. The insectivorous birds which feed on the lady birds are larger still and are only present in a small number and there may only be a single pair of hawks of much larger size than the insectivorous birds on which they prey.

Question 6.
Draw the diagram of number pyramid keeping foxes as third consumers. What are the consequences if their number increases?
Answer:

1. If the number of foxes increases, then the competition for food will be very severe and less amount of food will be available for them.
   
2. As a result some of the foxes may not get enough food and die due to starvation.
3. This reduces the population of foxes and very few foxes will be left in the forest.
4. This increases the chances of survival of secondary consumers birds, hence their number increases.
5. This increases the availability of food for foxes. Very soon a balance will be established between the number of secondary consumers and foxes.

Question 7.
What reasons are responsible for decrease in number of top carnivores and biomass starting production in a food chain?
(OR)
Why the number of organisms get decreased as we move from producers to consumer levels?
Answer:

1. In a food chain as we move from producers to different levels of consumers the energy available will decrease gradually.
2. Only ten percent of the energy present in one tropic level transfer to another tropic level.
3. Biomass also decreases gradually as only 10 – 20% of the biomass is transferred from one tropic level to the next in a food chain.
4. As there is less energy of less biomass available at top levels, number of organisms also less generally.
5. So the number of organisms get decreased as we move from producers to different level of consumer.

Question 8.
Show food chain of different organisms, number of pyramid of your school.
Answer:
Food chain of different organisms in our school:
Plant → aphids → spiders thirds.

1. The pyramid of organisms in a food chain can be represented graphically in a pyramid of number.
2. Each bar represents the number of individuals at each tropic level in a food chain.
3. At each link in a food chain, from the first order consumers to the large carnivores, there is normally an increase in size, but decrease in number.

Question 9.
What determines the terrestrial ecosystems on the earth?
Answer:

1. The terrestrial ecosystems on the earth are being determined largely by the variations in climatic conditions between the poles and equator.
2. The main climatic influences which determine these ecosystems are rainfall, temperature and availability of light from the sun.
3. For instance, forests are usually associated with high rainfall, but the type Is influenced by temperature and light.
4. The same applies to deserts which occur in regions where rainfall is extremely low.
5. Thus, the climatic conditions along the horizontal climatic regions determined the terrestrial ecosystems on the earth.
6. If we move from equatorial region to the polar region, we can come across tropical rain forests, savannah, deciduous forest, coniferous forests and then tundras respectively.
7. Similarly altitude of the place is also a determining factor.
8. If we climb a mountain such as Kilimanjaro in equatorial Africa, we can go through a comparable system of ecosystems, starting with tropical rain forest at the base and ending with perpetual snow and ice at the summit.

Question 10.
“All the energy in the ecosystem is ultimately derived from sunlight.” Justify.
Answer:

1. All the organisms in an ecosystem derive energy from food.
2. The food by its nature is the chemical energy and by in its stored form, it is the potential energy.
3. In an ecosystem, all the consumers at any level depend upon producers for their food either directly or indirectly.
4. The producers in any ecosystem are nothing but photosynthetic organisms such as plants, phytoplanktons and photosynthetic bacteria.
5. Energy enters the producers in the ecosystem from the sun in the form of solar energy during photosynthesis.
6. From the producers, the chemical energy passes to the consumers from one tropic level to the next through food.
7. For example, in a grassland ecosystem, grass traps the solar energy and stores in its body.
8. When this grass is eaten and assimilated by insects this stored energy enters into the body of insects.
9. From the insects it will pass to frog, from them to snake and so on to eagle.
10. Thus, all the energy in the ecosystem is ultimately derived from sunlight.

Question 11.
What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Answer:

1. The tendency of pollutants to concentrate as they move from one trophic level to the next trophic level is known as Biomagnification.
2. Plants absorb pesticides, heavy metals from the soil.
3. The primary consumers when eat these plants the remaining of pesticides and heavy metals enter their bodies.
4. As these chemicals are not degradable, they accumulate in the bodies of organisms of all trophic levels in the food chain.
5. Most of the plants products which we eat are grown in fields in which pesticides and fertilisers have been used.
6. These are absorbed by the plants and cannot be removed by washing or other means.
7. Human beings are at the top level of the food chain these chemicals get accumulated in our bodies and cause various disorders.
8. Levels of biological magnification would increase as the trophic level increases.

Question 12.
Will the impact of removing all the organisms in a trophic level be different for different trophic levels ? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
Answer:

1. If we remove producers from ecosystem, herbivores will not survive and the entire ecosystem collapse.
2. Removing herbivores result in increase number of producers and carnivores would not get food.
3. Removing carnivores result in increase of herbivores to unsustainable levels.
4. If we remove decomposers from ecosystem waste material and animal dead remains would pile up and nutrients would not be available to the producers.
5. Some or the other damage would be caused to the ecosystem if the organisms of any trophic level is removed.
6. However impact of removing producers or decomposers would be serve as the whole ecosystem would collapse.
7. Without plants sun’s energy cannot be converted to chemical energy which is the basis of life on earth.
8. Without decomposers the nutrients cannot be recycled and made available to producers.

Question 13.
Every organism has got the right to live on this planet. Write slogans to motivate the people on preservation of biodiversity.
Answer:

1. Live and let live.
2. Conserve nature – conserve life.
3. Clean the environment, live happily.
4. Think eco-friendly and live eco-friendly.
5. If we protect the environment, it protect us.
6. Reduce pollution – conserve the biodiversity.

Question 14.
Write some friendly ecosystem activities you will conduct in your school.
Answer:

1. Forming eco-clubs: These clubs consists of student representatives from each class. They will take up the eco-friendly activities and encourage the people of that village to follow environment friendly activities.
2. Setting up garden at school: This ensures the school and its premises green through planting of flowering plants, vegetables and fruit trees. It is a symbol of biodiversity because various plants and animals inhabit the garden.
3. Electricity conservation programme: To save energy the school implements certain hours to be switched off habit. This switching off programme for one hour from 3.30 p.m. to 4.30 p.m. help conserve electricity in every classroom.
4. Pollution prevention programme: A ‘no burning of trash policy should be implemented in the school. Waste materials are recycled and properly disposed to ensure a clean, waste-free environment.
5. Making compost by organic wastes: By digging a pit at one corner of the school and throwing the organic waste particularly of mid day meal waste into pit and covering with soil layers prepares compost which can be used as manure for plants. This creates a clean environment in the school.
6. Using cloth bags instead of polythene bags by pupil.
7. Collection of solid waste materials and proper management of its helps in reducing soil pollution.
8. Children should be encouraged to follow ‘3R’ system i.e. Reduce, Re use and Recycle different substances.

Question 15.
What is Ecological pyramid? Describe different types of Ecological pyramids.
Answer:

1. The graphical representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called ecological pyramid.
   
2. There are three types of ecological pyramids. They are
   1) Pyramid of number, 2) Pyramid of biomass and 3) Pyramid of energy.
3. Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem.
4. The shape of this pyramid varies from ecosystem to ecosystem.
5. In forest ecosystem the pyramid structure is partly upright and in parasitic food chain is inverted.
6. Pyramid of biomass is a graphical representation designed to show the quantity of living matter (bio mass) at each trophic level in a given ecosystem.
7. In terrestrial ecosystems, the biomass progressively decreases from producers to top carnivores hence the pyramid structure is upright whereas in aquatic ecosystem it is inverted.
8. Pyramid of energy is a graphical representation designed to show the quantity of energy present at each tropic level in a given ecosystem. The pyramid of energy is always upright.

Question 16.
Collect information regarding pesticides commonly used in your area and prepare a chart showing pesticide and common name and on which crop and pest it is commonly used.
Answer:

S.No.	Pesticide	Crop
1.	Imidaclopriol	Cotton, Chillies	Aphid, White fly, Jassids, Thrips
		Paddy	BPH, WBPH, GWT
2.	Triazophos	Cotton	Bollworm
		Paddy	Leaf folder, Green leaf hopper, Hispa
3.	Chlorpyriphos	Paddy	Leaf roller, Hispa gall midge, Stem borer, Whorl maggot
		Cotton	Aphid, Bollworm, White fly
4.	Monocrotophos	Paddy	Brown plant hopper, Green leaf hopper, Leaf roller, Yellow stem borer
		Maize Bengal gram Green gram Black gram	Shoot fly Pod borer
		Sugarcane	Early shoot borer, Mealy bug
		Cotton Oil seeds Vegetables	Insects
5.	Acephate	Cotton	Jassid, Bollworms
		Sunflower	Aphids
6.	Dichlorvos	Paddy	Leaf roller
		Sugarcane	Pyrilla
		Oil seeds, Vegetables	Insect pests
7.	Acetamiprid	Cotton	Aphids, Jassids, White flies

SCERT AP Board 8th Class Social Solutions 2nd Lesson Energy from the Sun Textbook Questions and Answers.

AP State Syllabus 8th Class Social Studies Solutions 2nd Lesson Energy from the Sun

8th Class Social Studies 2nd Lesson Energy from the Sun Textbook Questions and Answers

Question 1.
Correct the false statements.
a) If a place is closer to the sea, irrespective of its distance from the equator, it will always be cooler.
Answer:
True

b) As you go up higher from the earth, it becomes warmer because the sun is closer to you.
Answer:
False.
Correction: As you go up higher from the earth, it becomes cooler, because the temperature decreases at the rate of 6°C for every ascent of 1000 metres.

c) Sun heats the air first and then the earth.
Answer:
False.
Correction: Sun heats the earth first and then the air.

d) Global warming is related to oxygen.
Answer:
False.
Correction: Global warming is related to carbon-di-oxide.

Question 2.
What’s the difference between the highest temperatue in Table 2 and the lowest temperature in Table 1?

Table 1

Month	Maximum°C	Minimum °C
Jan	30	17
Feb	33	19
Mar	37	22
Apr	39	26
May	39	26
Jun	35	25
Jul	33	24
Aug	33	24
Sep	33	23
Oct	32	23
Nov	30	20
Dec	29	18

Table – 2

Month	Maximum°C	Minimum °C
Jan	32	19
Feb	32	21
Mar	32	23
Apr	33	25
May	33	26
Jun	30	24
Jul	29	24
Aug	28	24
Sep	29	24
Oct	32	24
Nov	33	22
Dec	32	21

Answer:
The highest temperature in Table 2 = 33°C
The lowest temperature in Table 1 = 17°C
The difference = 16°C

Question 3.
Suppose, the temperature in Moscow was – 8°C at 10 AM on 6 December. Twenty-four hours later it was 12°C higher. What was the temperature at 10 AM on 7 December?
Answer:
The temperature was 4°C.

Question 4.
Delhi and Mumbai are both situated on plains and their height above sea level is less than 300 metres. Why is there so much difference in their monthly average temperatures? In which months are the average temperatures in these two cities most similar? Can you explain?
Answer:
Mumbai experiences moderate climate while Delhi experiences extreme climate. This is because Mumbai’s coastal nature and tropical location ensures moderate temperature throughout the year. Delhi’s distance from the sea gives it an extreme type of climate.
The average temperatures in these two cities are more similar in the months of August and September.

Question 5.
Given below are the average monthly minimum and maximum temperatures of Jodhpur. Make a line graph of them. Which are the hottest and coldest months of the year?
Table: Average Monthly Maximum Temperatures in Jodhpur, Rajasthan (°C).

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Minimum	09	12	17	22	27	29	27	25	24	20	14	11
Maximum	25	28	33	38	42	40	36	33	35	36	31	27

Answer:
a) April, May and June are the hottest months in the year.
b) December, January and February are the coldest months in the year.

Question 6.
Given here are the average maximum temperatures of three places: A, B, and C. Make graphs of them. What can you guess about each place by looking at the Table and graphs?

Place	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
A	23	26	33	38	41	39	34	33	33	33	29	25
B	-3	1	6	12	17	21	25	24	21	14	8	2
C	31	32	33	32	32	29	29	29	30	30	30	31

Answer:
A and C are in hot regions and B is in cold region.

Question 7.
Give three possible explanations for the differences between the average temperatures in Thiruvananthapuram and Shimla in January.
Answer:

1. Tiruvananthapuram is situated on sea coast.
2. Shimla is on high altitude.
3. Tiruvananthapuram is near to the equator and Shimla is far away from the equator.

Question 8.
Between Bhopal, Delhi, Mumbai and Shimla, which two places show a similar temperature pattern? How can you explain the similarity between these two places?
Answer:
Bhopal and Delhi show a similar temperature pattern. This is because these two are far away from the sea.

Question 9.
Look at the graph of Minimum – Maximum temperature given below and answer the questions below.
a) What is the average highest temperature in July?
Answer:
28°C

b) How warm does it usually get in December?
Answer:
26°C

c) How cool does it usually get in June?
Answer:
20°C

d) Is there a bigger difference between night and day temperature in May or in August?
Answer:
In the month of May

e) When is summer?
Answer:
March, April and May months.

Question 10.
Nithin says thermal power is better to use, but Padmaja says that Solar Energy is better. Which of them do you support? Why?
(OR)
How is solar energy better than thermal power?
Answer:
Solar energy is better than thermal power because solar energy is clean, breath-takingly abundant and is a responsible renewable resource to meet much of the world’s energy needs, as well as a fundamental need of our body for vitamin D.

Question 11.
Read the para under the title “Height and Temperature” and comment on it.

At the peak of summer some people go from the plains to hilly places such as Ooty or Shimla to avoid the heat. Even in the summer months, the temperatures are low on high hills. The highest parts of a mountain generally have the lowest temperatures. Temperatures decreases with elevation (height).

Answer:
The temperature decreases with altitude. On an average, the temperature decreases by 3.5°F for every 1000 ft of altitude (6.5°C for every 1000 metres).
Additional information: The lapse rate depends on, if the air is dry or moist – in dry air, the temperature decreases more quickly, in moist air more slowly.

8th Class Social Studies 2nd Lesson Energy from the Sun InText Questions and Answers

Question 1.
Can you point out the difference between insolation and radiation? (Textbook Page No. 19)
Answer:
Insolation: The radiation received on the surface of a body is called insolation.
Radiation: When a body gives out energy it is called radiation.

Question 2.
What will happen if the atmosphere gets more polluted with smoke and duct? (Textbook Page No. 19)
Answer:
Some amount of solar rays are absorbed or reflected away by smoke or dust in the atmosphere. If the atmosphere gets more polluted with smoke and dust, it may absorb more heat. As a result the temperatures on the earth may raise. If it reflects more, there will not be heat on the earth. Both are dangerous to ‘the life’ on ‘the earth’.

Question 3.
Can you tell why there is difference in heating of land and water? (Textbook Page No. 21)
Answer:
The water is transparent and lets energy pass through. On the other land, the sun heats up only the top layer of the land. This is because the land is solid. A solid is opaque and does not let energy through. This is the difference in heating of land and water.

Question 4.
a) Where will the rays fall more slanting – in Japan or North Pole? (Textbook Page No. 20)
Answer:
In North pole.

b) Where will Sun’s rays fall more intensively, in Andhra Pradesh or Rajasthan?
Answer:
In Andhra Pradesh.

c) If the Earth is flat and not curved, then which will get more heat – Japan or the Equator, or both equally?
Answer:
Both equally,

d) Look at the globe and say which countries wifi be hotter and which will be cooler?
Answer:

1. Australia, Indonesia, Philippines, Cambodia, India, Chile, Brazil, Sudan, Uganda, etc. -hotter.
2. North America, Iceland, Scandinavia and Russia, etc. – cooler.

Question 5.
To get an idea of other temperatures, measure and note the temperature of the following things. Before you start measuring, guess the temperature of each one. (Textbook Page No. 23)

Thing	Temperature, °C
	Guess	Measurement
Water in bucket
Ice
Giass of cold water
Warm bath water

Answer:

Thing	Temperature, °C
	Guess	Measurement
Water in bucket	25°C	35°C
Ice	0°C	0°C
Glass of cold water	15°C	10°C
Warm bath water	70°C	76°C

Question 6.
It is safer and advisable to use thermometers that have a scale of -10°C to 110°C. Using such a thermometer, also measure and note the temperature of boiling water and hot tea. (Textbook Page No. 23)
Answer:

1. Temperature of boiling water: 100°C
2. Temperature of hot tea: 95°C,

Question 7.
Look at the number line below, you can see how + and – numbers are marked. (Textbook Page No. 24)

a) Which temperature is greater: 5°C or -5°C?
Answer:
5°C

b) At which of these two temperatures will we feel colder?
Answer:
-5°C

c) How many degrees difference is there between -5° and 5°?
Answer:
10°C

d) Write in short form each of the following temperatures:
i) 88 degrees below zero, Celsius
Answer:
-88°C
ii) 38 degrees above freezing, Celsius
Answer:
38°C
iii) 32 degrees below freezing, Celsius
Answer:
-32°C

e) Did you note the temperature in your classroom today? 88 degrees below zero Celsius is how many degrees lower than the temperature you measured?
Answer:
Classroom temperature = 28°C It is 116°C low.

f) The temperature of a normal human body is 37°C. How much hotter than normal body temperature is 50°C?
Answer:
13°C

g) How much colder than the normal body temperature is -5°C?
Answer:
42°C

h) Arrange the following temperatures from the highest to the lowest:
12°C, -16°C, 29°C, 0°C, – 4°C.
Answer:
29°C, 12°C, 0°C, -4°C – 16°C.

i) At which of the above temperatures will we feel hottest?
Answer:
At 29°C

j) At which of the above temperatures will we feel coldest?
Answer:
At -16°C.

Question 8.
Have you been to places that have different climate than where you live? Describe it in the class. (Textbook Page No. 18)
Answer:
I live in Vijayawada It is very hot place. I have been to Ooty during last vacation. It is a hill station in Tamilnadu. It is situated on Nilgiri hills. I went from Vijayawada to Coimbatore and there to Ooty. It is ‘queen of hill stations’. It is too cool as it is situated on high altitude. There I stayed in a hotel opposite to ‘Horse Race Course’. There I visited Dodabetta peak, Love Dale, Wildlife Sanctuary, Botanical Gardens, Emerald lake etc., in Ooty. There I enjoyed the cold in summer. I took a resolution on the 1st January of this year that I would visit Ooty often in my life. I love the memories of my trip.

Question 9.
Table 1: (Average monthly temperature of Ananthapuram)

Month	Maximum,°C	Minimum, °C
Jan	30	17
Feb	33	19
Mar	37	22
Apr	39	26
May	39	26
Jun	35	25
Jul	33	24
Aug	33	24
Sep	33	23
Oct	32	23
Nov	30	20
Dec	29	18

Use the data in the Table 1 and plot the average minimum monthly temperatures for Ananthapuram on the same graph paper in which the graph of maximum temperatures is drawn for your understanding. The first two months have already been done for you in the Graph 1.

Look at the data and the graph and answer the following questions about Ananthapuram:
a) How cold does it usually get in November in Ananthapuram?
Answer:
20°C

b) Which month has the highest maximum temperature in Ananthapuram?
Answer:
April and May, 39°C

c) What is the difference between the highest maximum temperature and the lowest maximum temperature in the year?
Answer:
22°C.

d) Which three months are the hottest in Ananthapuram?
Answer:
March, April and May.

e) Which three months are the coldest?
Answer:
December, January and February

f) What is the average maximum temperature in January in Ananthapuram?
Answer:
30°C

g) From June through December, the average minimum monthly temperature keeps falling in Ananthapuram. Does the average maximum monthly temperature also keep falling?
Answer:
Yes, It is also falling.

h) What is the difference between the maximum and minimum temperature in May?
Answer:
13°C

i) What is the difference between the maximum and minimum temperature in August?
Answer:
9°C

j) Based on your answers to the above two questions, is there a larger difference between the maximum and minimum temperatures in the summer or in rainy season in Ananthapuram?
Answer:
There is not much variation.

Question 10.
Table 2: (Average monthly temperature)

Month	Maximum,°C	Minimum, °C
Jan	32	19
Feb	32	21
Mar	32	23
Apr	33	25
May	33	26
Jun	30	24
Jul	29	24
Aug	28	24
Sep	29	24
Oct	32	24
Nov	33	22
Dec	32	21

The average of maximum and minimum monthly temperatures are plotted on the Graph 2.
a) Which month has the lowest minimum temperature in Visakhapatnam? How much is it?
Answer:
In the month of January; It is 19°C.

b) Which is the hottest month in Visakhapatnam? How much was the average maximum temperature for that month?
Answer:
April, May and November months are too hot; 33°C.

c) Compare the temperatures of Ananthapuram and Visakhapatnam to answer the following:
i) In January, which place is colder?
Answer:
Ananthapuram
ii) In June, which place is hotter?
Answer:
Ananthapuram
iii) In which place, Ananthapuram and Visakhapatnam does the temperature remain more or less the same throughout the year?
Answer:
Visakhapatnam

Question 11.
Observe the following graphs.

Now answer the following questions.
a) Can you think of any other reason for this state of temperature?
Answer:
Due to altitude, mean sea level, etc. the state of temperature differs.

b) What will happen if the inversion occurs?
Answer:
When inversion occurs cold air underlies warmer air.

c) How many metres higher than Delhi is Shimla?
Answer:
Shimla is 1900 metres higher than Delhi.

d) Based on the difference in elevation, calculate the likely difference in temperature between the two places.
Answer:
Approximately 12°C.

e) Which month has the highest maximum temperature in Shimla? How much is the temperature?
Answer:
May month, it is 22°C.

f) Which month has the highest maximum temperature in Deihi? How much is it?
Answer:
May month. It is 40°C.

g) In September, the average maximum temperature in Shimla is ———–°C while in Delhi, it is ———–°C.
Answer:
17°C, 34°C.

h) Which is colder: Delhi in January or Shimla in July?
Answer:
Delhi in January is colder.

Question 12.
Sometimes, especially in mornings of winters, coal temperatures are found near the ground. You can see dew drops on the grass due to condensation. The cooler temperatures near the ground level are due to less amount of insolation received due to the shorter days and excessive radiation due to the longer nights. This is known as inversion. (Textbook Page No. 28)
a) Can you think of any other reason for this state of temperature?
Answer:
I find no other reason.

b) What will happen if the inversion occurs?
Answer:
When inversion occurs cold air underlies warmer air.

Question 13.
Observe the following graph.

a) Which of the three places shown in the graph is located near to the Equator?
Answer:
Singapore

b) What is the average yearly temperature in that place?
Answer:
27.8°C

c) Does it usually get much warmer in the summer than in the winter there?
Answer:
No, there is slight difference.

d) Is summer in Vladivostok warmer than the winter in Singapore?
Answer:
No, there is much difference.

e) Does it usually get warmer in July in Singapore or in Shanghai?
Answer:
Singapore

f) Which of the three places on the graph has the most extreme climate?
Answer:
Vladivostok

g) What is the warmest month in Shanghai?
Answer:
July and August

h) What is the average yearly temperature there?
Answer:
15.3°C

i) Which month has the lowest average maximum temperature in this place?
Answer:
January and February.

Question 14.
Use the maps in your Atlas to find out the latitude and the average temperature in January of each of the following places: The first one has already been done for you.

Place	Lat.	Temp, in January
Vijayawada, A.P.	17° N	between 20 and 22.5° C
Agra, U.P.
Madurai, T.N
Nagpur, M.H

a) According to this map, there is no place in India that has an average January temperature higher than 30°C. (Remember, this is the average. There may be some January days in some places that do get hotter than 30°C.)
Look at the map and find out which parts of India usually have the highest average temperature (in January).
b) If you look north from this place on the map, is the average January temperature higher or lower?
Answer:

Place	Lat.	Temp, in January
Vijayawada, A.P.	17°N	between 20 and 22.5° C
Agra, U.P.	27°N	22.3°C- 8°C
Madurai, T.N	9.93°N	30°C – 20°C
Nagpur, MH	21 °N	28°C – 12°C

a) Southern parts of India have the highest average temperature.
b) It is lower.

Question 15.
Why is the North cooler in winter? (Textbook Page No. 30)
Look at the following table, it shows sunrise and sunset in different cities in India on 10th January.

Place	Sunrise	Sunset
Visakhapatnam, A.P.	6:29	5:38
Agra, U.P.	7:09	5:42
Madurai, T.N.	6:37	6:12
Nagpur, MH	6:53	5:48
Hyderabad, T.S.	6:49	5:58
Kohima, Nagaland	6:02	4:40

Answer the questions below:
a) In which of these six cities does the sun rise first?
Answer:
Kohima (Nagaland)

b) In which of these cities does the sun set last?
Answer:
Madurai.

Question 16.
Find out the locations of Singapore, Shanghai and Vladivostok on the following picture of the globe.
Answer:

Project work
Question 1.
You know that the Sun is the source of heat on the Earth. But why do you think the heat varies from morning to night or from season to season and from place to place? We are listing some variations here. Try to think a reason for it and discuss in the class before you proceed to read this chapter. (Textbook Page No. 18)

1. Cool in the early morning and warmer in the afternoon.
2. Warm in summer and cool in winter.
3. Cool on hill tops and warm in the plains.
4. Warm in Equatorial region and cold in Polar region.

Answer:
The heat on the earth varies from morning to night or from season to season and from place to place. The reasons are latitude, altitude, distance from the sea, ocean currents, mountain barriers, air masses and prevailing wind system.
Reason 1: In the morning the Sun’s rays are slanting on a particular place. In the afternoon they are straight on the same place. This is due to rotation.

Reason 2: During the summer the Sun’s rays hit the earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also the long day light hours allow the earth plenty of time to reach warm temperatures. This is due to revolution.

Reason 3: The average rate of decrease of the temperature of normal air with the increase in height. It is equal to 6°C/km. (Normal Lapse Rate)

Reason 4: The Sun’s rays fall straight on the equatorial region and starting on the poles.
This is due to curvature of the earth.

Question 2.
Measure the temperature for a week in different months throughout the year. You will be able to see the temperature differences that occur between the summer, winter, monsoon, and other seasons. (Textbook Page No. 23)
a) For the next week, measure the air temperature each day at the same time and place (Remember to choose a place that Is in the shade). Each day before you measure, write down your guess. Keep your record in a separate notebook.
Place: ———–
Time: ———–
Month: ———–

Date	Air Temperature, °C
	Guess	Measurement

b) Record the temperature every day for one week for few months.
c) Calculate the weekly average temperatures.
d) Discuss the variations between different weeks.
Answer:
Place: Bengaluru
Time: 12 Noon
Month: January

	Air Temperature, °C
Date	Guess	Measurement
18.1.2016	28°C	29°C
19.1.2016	27°C	30°C
20.1.2016	29°C	30°C
21.1.2016	29°C	30 C
22.1.2016	28°C	30°C
23.1.2016	27°C	30°C
24.1.2016	28°C	30°C

SCERT AP 7th Class Maths Solutions Pdf Chapter 4 Lines and Angles Ex 4.4 Textbook Exercise Questions and Answers.

AP State Syllabus 7th Class Maths Solutions 4th Lesson Lines and Angles Exercise 4.4

Question 1.
In the given figure, two lines p ∥ q and r are transversal, If ∠3 = 135°, then find the remaining angles.

Answer:
Given ∠3 = 135
∠1 = ∠3 = 135° (vertically opposite angles)
∠1 = ∠5 = 135° (corresponding angles)

∠3 = ∠8 = 135° (corresponding angles)
∠3 = ∠5 = 135° (Alternate interior angles)

∠1 + ∠7 = 180° (co-exterior angles are supplementary)
135° + ∠7 = 180°
∠7 = 180°- 135° = 45°
∠6 = ∠7 = 45° (vertically opposite angles)
∠6 = ∠2 = 45° (corresponding angles)
∠4 = ∠7 = 45° (corresponding angles)
∴ ∠1 = 135°, ∠2 = 45°, ∠3 = 135°, ∠4 = 45°, ∠5 = 135°, ∠6 = 45°, ∠7 = 45°, ∠8 = 135°

Question 2.
In the given figure, \(\overleftrightarrow{\mathbf{AB}}\) || \(\overleftrightarrow{\mathbf{CD}}\) and \(\overleftrightarrow{\mathbf{DE}}\) is a transversal. Find x.

Answer:
Given \(\overleftrightarrow{\mathbf{AB}}\) || \(\overleftrightarrow{\mathbf{CD}}\) and \(\overleftrightarrow{\mathbf{DE}}\) is a transversal line.
∠ABE = ∠CDB (corresponding angles)
∠ABF + ∠FBE = ∠CDB (we know ∠ABE = ∠ABF + ∠FBE)
From the figure ∠ABF = 35°,
∠FBE = x° and ∠CDB =100°
35° + x = 100°
⇒ 35° + x – 35° = 100° – 35°
∴ x = 65°

Question 3.
In the given figure, m || n and p is transversal. Find x and y.

Answer:
Given m || n and p is transversal.
So, ∠x = 120° (vertically opposite angles)
45 + y = x (corresponding angles)
⇒ 45 + y = 120° (we know ∠x = 120°)
⇒ 45 + y – 45 = 120-45°
⇒ y = 75°
x = 120° and y = 75°

Question 4.
In the given figure, \(\overrightarrow{\mathbf{A B}}\|\overrightarrow{\mathbf{C D}}\| \overrightarrow{\mathbf{F E}}\). Find x, y and ∠AEC.

Answer:
Given \(\overrightarrow{\mathbf{A B}}\|\overrightarrow{\mathbf{C D}}\| \overrightarrow{\mathbf{F E}}\)
∠x = 20° (Alternate interior angles)
∠y = 33° (Alternate interior angles)
∠AEC = ∠AEF + ∠FEC
∠AEC = ∠x + ∠y
∠AEC = 20° + 33° = 53°
∴ x = 20°, y = 33° and ∠AEC = 53°

Question 5.
In the given figure, a transversal t intersects two lines p and q. Check whether p ∥q or not.

Answer:
If co-interior angles are supplementary, then the lines are parallel.
100° + 80° = 180° (co-interior angles supplementary)
So, p and q are parallel to each other.

Question 6.
In the given figure if l ∥m, then find x, y and z.

Answer:
Given l ∥m and AC is transversal.
z = 40° (Alternate interior angles)
l ∥m and AB is transversal. , and x + (y + z) = 180° (co-interior angles are supplementary)
x + y + z = 180°
(x + y) + 40° = 180° (co-interior angles are supplementary) (∵ z = 40°)
x + y + 40° = 180°
x + y + 40°-40° = 180° – 40°
∴ x + y = 140°
But x = y (given)
2x = 140°
∴ x = \(\frac{140^{\circ}}{2}\) = 70° = y
So, x = 70°, y = 70° and z = 40°

Question 7.
In the given figure p, q, r and s are parallel lines and t is a transversal. Find x, y and z.

Answer:
p ∥ q
So, 80° + x = 180° (co-interior angles)
80° + x-80° = 180°-80°
x = 100°

q ∥ r
x + y = 180° (co-interior angles)
100° + y = 180° (we know x – 100°)
100° + y – 100° = 180°- 100°
y = 80°

r∥s
y = z (Alternate exterior angles)
y = z = 80° (we know y = 80°)
x = 100°, y = 80° and z = 80°

Question 8.
In the given figure \(\overrightarrow{\mathbf{A B}} \| \overrightarrow{\mathbf{C D}}\) and E is a point in between them. Find x + y + z. (Hint : Draw a parallel line to \(\overrightarrow{\mathbf{A B}}\) through E)

Answer:
Given \(\overrightarrow{\mathbf{A B}} \| \overrightarrow{\mathbf{C D}}\)

Draw \(\overrightarrow{\mathrm{EF}} \| \overrightarrow{\mathrm{AB}}\)
∠BAE = x,
∠AEF = p
∠FEC = q,
∠ECD = z
∠AEC = ∠AEF + ∠FEC
y = p + q

AB ∥ EF and AE is a transversal.
∠BAE + ∠AEF = 180° (co-interior angles are supplementary)
x + p = 180° ……………….(1)
CD ∥ EF and EC is a transversal.
∠FEC + ∠ECD = 180° (co-interior angles are supplementary’)
q + z = 180° …………….(2)

By adding (1) and (2)

x + y. + z = 360° (we know y = p + q)

Question 9.
Identify the pair of parallel lines in the given figure and write them.

Answer:
∠A = ∠E = 60° So, AL ∥ EH
∠B = ∠D = 90° So, BK ∥ DL
∠C = ∠F = 50° So, CJ ∥ FG

AP State Board Syllabus AP SSC 10th Class Maths Textbook Solutions Chapter 4 Pair of Linear Equations in Two Variables Ex 4.2 Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Maths Solutions 4th Lesson Pair of Linear Equations in Two Variables Exercise 4.2

10th Class Maths 4th Lesson Pair of Linear Equations in Two Variables Ex 4.2 Textbook Questions and Answers

Form a pair of linear equations for each of the following problems and find their solution.
Question 1.
The ratio of incomes of two persons is 9 : 7 and the ratio of their expenditures is 4 : 3. If each of them manages to save Rs. 2000 per month, find their monthly income.
Answer:
Given ratio of incomes of two persons = 9 : 7
So let the incomes of each = Rs. 9x and Rs. 7x
and ratio of expenditures = 4 : 3
So let the expenditures of each = 4y and 3y
then earnings of each = (income – expenditure) of each
⇒ 9x – 4y = Rs. 2000 and 7x – 3y = 200
∴ 9x – 4y = 7x – 3y = 2000
⇒ 9x – 7x = 4y – 3y
⇒ y = 2x
now putting y = 2x in 9x – 4y = 2000 we get
9x – 4(2x) = 2000 ⇒ x = 2000
∴ Income of each = 9x = 9(2000) = 18000
and 7x = 7(2000) = 14,000

Question 2.
The sum of a two digit number and the number obtained by reversing the digits is 66. If the digits of the number differ by 2, find the number. How many such numbers are there?
Answer:
Let the digit in units place be x
and the digit in tens place be y
then the value of the number = 10y + x
Number obtained by reversing the digits = 10x + y
By problem,
(10y + x) + (10x + y) = 66
and x – y = 2
⇒ 11x – 11y = 66 and x – y = 2
⇒ x + y = 6 and x – y = 2
Solving these two equations
x + y = 6
x – y = 2
(+) 2x = 8
x = \(\frac{8}{2}\) = 4
Substituting x = 4 in x + y = 6
we get 4 + y = 6 ⇒ y = 2
Substituting x, y values in equations (10y + x) & (10x + y),
We get 10y + x
= 10(2) + 4 = 20 + 4 = 24
and 10x + y = 10(4) + 2
= 40 + 2 = 42
∴ The number is 42 or 24
Thus we have two such numbers.

Question 3.
The larger of two supplementary angles exceeds the smaller by 18°. Find the angles.
Answer:
Let the pair of supplementary angles be x and y [and x > y]
then we have x + y = 180° …… (1)
By problem, x = y + 18°
⇒ x – y = 18° …… (2)
Solving the equations (1) and (2) we get

and x = \(\frac{198}{2}\) = 99°
Substituting x = 99° in equation (2) we get
99° – y° = 18°
⇒ y° = 99° – 18 = 81°
∴ The angles are 99° and 81°.

Question 4.
The taxi charges in Hyderabad are fixed, along with the charge for the distance covered. For a distance of 10 km., the charge paid is Rs. 220. For a journey of 15 km. the charge paid is Rs. 310.
i) What are the fixed charges and charge per km?
ii) How much does a person have to pay for travelling a distance of 25km?
Answer:
Let the fixed charge be = Rs. x.
and the charge per one km = Rs. y.
By problem, x + 10y = 220 x + 15y = 310
Solving (1) and (2) we get

∴ y = \(\frac{-90}{-5}\) = 18
i.e., charge per one km = Rs. 18
Substituting y = 18 in equation (1) we get
x + 10 × 18 = 220
⇒ x = 220 – 180
⇒ x = Rs. 40
∴ Fixed charge = Rs. 40;
Charge per km = Rs. 18.

ii) Now, the charge for travelling a distance of 25 km = 25 × 18
= Rs. 450 + 40
= Rs. 490

Question 5.
A fraction becomes equal to \(\frac{4}{5}\) if 1 is added to both numerator and denominator. If, however, 5 is subtracted from both numerator and denominator, the fraction becomes equal to \(\frac{1}{2}\). What is the fraction?
Answer:
Let the numerator of the fraction = x
and the denominator of the fraction = y
By problem,
\(\frac{x+1}{y+1}\) = \(\frac{4}{5}\) and \(\frac{x-5}{y-5}\) = \(\frac{1}{2}\)
⇒ 5(x + 1) = 4(y + 1) and 2(x – 5) = 1(y – 5)
5x + 5 = 4y + 4 and 2x – 10 = y – 5
⇒ 5x – 4y = 4 – 5 and 2x – y = – 5 + 10
⇒ 5x – 4y = – 1 …… (1)
and 2x – y = 5 …… (2)

∴ y = \(\frac{-27}{-3}\) = 9
Substituting y = 9 in equation (2) we get
2x – 9 = 5
⇒ 2x = 5 + 9
⇒ 2x = 14 and
x = \(\frac{14}{2}\) = 7
Thus the fraction is \(\frac{x}{y}\) = \(\frac{7}{9}\)

Question 6.
Places A and B are 100 km apart on a highway One car starts from A and another from B at the same time at different speeds. If the cars travel in the same direction, they meet in 5 hours. If they travel towards each other, they meet in 1 hour. What are the speeds of the two cars?
Answer:

Let the speed of the car which started from the place A = x kmph
and B = y kmph
Distance travelled by first car in 5h = 5x and in 1h = x
The distance covered by second car in 5h = 5y and in 1h = y
By problem when travelled in same direction,
5x – 5y = 100 ⇒ x – y = 20 …… (1)
and when travelled towards each other
x + y = 100 ……. (2)
Solving (1) and (2),

∴ x = \(\frac{120}{2}\) = 60
Substituting x = 60 in equation (1) we get
60 – y = 20
⇒ y = 60 – 20 = 40 kmph
Thus the speed of the cars are 60 kmph and 40 kmph.

Question 7.
Two angles are complementary. The larger angle is 3° less than twice the measure of the smaller angle. Find the measure of each angle.
Answer:
Let the pair of complementary angles be x° and y° with x° > y°
then x° + y° = 90° and
By problem
x = 2y – 3° ⇒ x – 2y = – 3°
Solving these two equations we get,

∴ y = \(\frac{93}{3}\) = 31°
Substituting y = 31°in x + y = 90° we get
x + 31° = 90°
⇒ x = 90° – 31° = 59°
The angles are 59° and 31°.

Question 8.
An algebra textbook has a total of 1382 pages. It is broken up into two parts. The second part of the book has 64 pages more than the first part. How many pages are in each part of the book?
Answer:
Let the first part of the book contains x pages
and the second part of the book contains y pages By problem,
x + y = 1382 ….. (1)
y = x + 64 ⇒ x – y = -64 …… (2)
Solving equations (1) and (2) we get

∴ x = \(\frac{1318}{2}\) = 659
Substituting x = 659 in equation (1) we get
659 + y = 1382
⇒ y = 1382 – 659 = 723
∴ The number of pages in the first part = 659
Second part = 723

Question 9.
A chemist has two solutions of hydrochloric acid in stock. One is 50% solution and the other is 80% solution. How much of each should be used to obtain 100 ml of a 68% solution?
Answer:
Let the first solution contains 50% acid.
Second solution contains 80% acid.
Let x ml of 1st solution and y ml of second solution are added.
Then x + y = 100
Acid content in the ‘mix’ is 50% of x + 80% of y = 68%

∴ y = \(\frac{180}{3}\) = 60
Substituting y = 60 in equation (1) we get
x + 60 = 100
⇒ x = 100 – 60 = 40
∴ Quantity of first solution = 40 ml
Quantity of second solution = 60 ml

Question 10.
Suppose you have Rs. 12000 to invest. You have to invest some amount at 10% and the rest at 15%. How much should be invested at each rate to yield 12% on the total amount invested ?
Answer:
Let the amount to be invested @ 10% be Rs. x
and the amount to be invested @ 15% be Rs. y
By problem x + y = 12000 ……. (1)
Also 10% of x + 15% of y = 12% of 12000

⇒ y = \(\frac{-24000}{-5}\) = Rs. 4800
Substituting y = 4800 in equation (1) we get
x + 4800 = 12000
⇒ x = 12000 – 4800 = 7200
The invested @ 10% = Rs. 7200
@ 15% = Rs. 4800