AP State Syllabus AP Board 8th Class Biology Solutions Chapter 8 Production and Management of Food From Plants Textbook Questions and Answers.
AP State Syllabus 8th Class Biology Solutions 8th Lesson Production and Management of Food From Plants
8th Class Biology 8th Lesson Production and Management of Food From Plants Textbook Questions and Answers
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Question 1.
State reasons why wheat is cultivated in Kharif.
Answer:
- The crops grown in the rainy season are termed as Kharif in the months of June to October.
- If we cultivate wheat crop in the month of July it takes 8 – 10 weeks for growing.
- After that flowering will take place. By that time, it would be October.
- Then the night duration extends more than 12\(\frac{1}{2}\) hours. Wheat plants flowering takes place only in long night durations.
- Crop production is based on the flowering of plant. If flowering of plant is more, the crop production also is more.
- Wheat is important cereal crop gained a lot through Green Revolution by developing high yielding hybrid strains.
Question 2.
Ramaiah’s field is flattened. Somaiah’s field has many up and downs. Who will get more crop ?
Answer:
- Generally the fields have a lot of ups and downs even after ploughing. So a leveller is used for levelling the soil.
- By levelling the soil, it becomes flattened, water and nutrients can be reached to every part of the land. It also helps in sowing seeds and planting.
- Because Ramaiah’s field is flattened, he will get more produce than Somaiah.
Question 3.
What are the advantages of ploughing?
Answer:
Before growing crops ploughing the soil properly is necessary.
Advantages:
- Ploughing loosens the soil and it helps in easier transportation of air and water.
- Water is stored deeply for a long time as the soil is soft.
- Roots penetrate in the deep and can respire well as the air enters easily into the soil.
- Friendly microorganisms and earthworms can grow well when the soil is soft.
- Some foe microorganisms die due to the sun rays.
Question 4.
Treating with fungicides before sowing the seed is necessary. Why?
Answer:
- Sometimes farmers wash seeds with chemicals to protect from pests.
- Medication is done to keep away the seeds from the harmful microorganisms like bacteria, fungi etc.
- So, generally farmers treat the seeds with fungicides before sowing the seeds before making them to germinate.
Question 5.
Why do farmers dry the paddy crop after cutting them from fields?
Answer:
- Naturally food produce can be damaged by fungi, pests, rats and bacteria.
- If moisture is also there in the grains, it helps to develop moulds (fungi).
- Such grains neither germinates nor suitable to eat.
- To overcome this problem farmers dry the grains for 2-3 days in sun.
- After drying they keep the grains in jute bags and preserve them in godowns.
Question 6.
Give some examples of plants that grow after replanting.
Answer:
Seeds that are broadcast in a plot, grow into seedlings. When these plants grow to certain height, farmers pick out the plants (seedlings) from the plots, make bundles and are sown in proper distances. This is called transplantation (replanted)
E.g.: Rice (Sri Vari), Tobacco, Onions, Chillies etc.
Question 7.
Rahim removed weeds in his crop field, but David did not. Guess who get more yield. Why?
Answer:
- Rahim get more yield than David. Because
- Weeds are the unwanted or undesirable plants which grow in the fields and compete with crop plants for water, nutrients, light and space.
- Because of these plants the crop plants may not grow properly. So they should be removed.
- Otherwise the yield of the crop will be reduced.
- Weeds give shelter for insects, pests and microorganisms and serve as a host for them.
- Weeds are capable of germinating and growing fastern than crop plants. They flower and form seeds much earlier than the crop plants.
- Some weeds disperse pollen grain to air which in turn causes respiratory diseases.
Question 8.
What is natural manure? How to prepare it? Give two examples.
Answer:
Natural manure: A manure made by the decomposition of plants and animal (organic) wastes is called natural manure or natural fertilizer or Bio Fertilizer.
Preparation:
- These fertilizers are formed by decomposing plant and animal wastes.
- In rural areas farmers keep these plant and animal wastes outside the village in open space.
- Some bacteria like Azatobacter, Nitrobacter decompose and it becomes manure which contain nutrients.
- Wherever the manure is added to the soil, there it provides nutrients to the plants. Examples : Vermi compost, Dung fertilizer.
Question 9.
Why do farmers plough their field during summer?
Answer:
- Ploughing loosens the soil and it helps in easier transportation of air and water.
- In summer temperature is very high. So the soil becomes dry. Then the soil becomes very loosly.
- Some foe microorganisms die due to the sunrays.
Question 10.
Rajendar cultivated cotton crop in his field. He did not get sufficient yield. Can you guess the reasons? (OR)
A farmer cultivated cotton crop in his field. He did not get sufficient yield. Guess any four causes for it.
Answer:
- Farmers in our state generally purchase seeds in the nearby market. The grains that are available in the packets play vital role in agriculture.
- Sometimes the rate of germination of the seeds is not up to the mark, which was labelled on the packet.
- Sometimes never germinate too.
- At times, seeds grow into plants but they be sterile.
- And sometimes the crop may be attacked by the larva of spotted brown boll-worm and pinkish boll-worms.
- The larva of brown catter pillar sucks the juice from the leaves. The buds and the fruits of cotton plants drop off from the infected plants.
- The larva of pinkish boll worm of cotton make hole in the stem, flower buds, flowers and fruits. As a result flower buds, cotton bolls drop off.
- May be these reasons Rajendar did not get sufficient yield.
Question 11.
I am a plant. I grow in crop fields. Farmers pluck me. I do not know the reason. Can you tell who am I ?
Answer:
- We observe some other plants growing along with the crop plants These are undesirable plants called weeds. They should be removed immediately.
- The weeds, compete with the crop plants for nutrients, water and light, so he crop plants may not grow properly. This is the reason why they (weeds) should be removed.
- Besides competition for food, light and water they also work as a carrier for different diseases. They also serve as host for different pests.
- Some weeds disperse pollen grains to air which in turn causes respiratory diseases.
- So the farmers pluck the weeds from crop plants by using different methods.
Question 12.
What do you observe in the experiment of dropping a fist of Bengal gram seeds in water?
a) What are the differences you observed in both the seeds?
Answer:
We can observe some seeds floated on water, the remaining sank under the water. The seeds which are floated are wrinkled and rough shaped but the sank seeds are round and smooth.
The floated seeds are light in weight but the sank seeds are more in weight.
b) Do you know why the floated seeds are lighter in weight?
Answer:
The floated seeds are not healthy, so they are lighter in weight.
c) Which seeds germinate well? Why?
Answer:
The seeds which sank in water germinate well because they are healthy.
d) Which seeds would not germinate properly? Why?
Answer:
The seeds which are wrinkled and rough would not germinate properly. Because the cotyledon inside the seed would not develop healthy.
Question 13.
Go to your nearest fertilizer shop and collect the information about chemical fertilizers and fill the table. Copy the following table in your notebook.
Answer:
Question 14.
Prepare a flow chart from ploughing to yielding in paddy.
Answer:
Question 15.
How do you appreciate the irrigation systems used in the drought prone areas?
Answer:
- This method is employed when the availability of water is poor.
- As the water reaches the plants drop by drop this is called Drip irrigation.
- A long tube followed by small tubes attached to a motor. The tubes are made holes. So the water comes out from the tube.
- The holes are arranged in such a way that it provide water exactly at the place where plant roots could receive water.
- The man’s best technical method of utilizing the water in farming where the conditions are pravailing and in the areas where the availability of water is scanty.
Question 16.
Narendra sprayed over dose of pesticides on his cotton crop. Ramesh says it is a hazard to biodiversity and crop yield. Can you support Ramesh? How?
Answer:
- In agriculture pests damage the crops. Almost all crops are generally effected by pests.
- Wheat, Paddy and suagarcane are generally affected by fungal diseases. Groundnut is affected by Tikka disease. The catterpillars of spotted brown boll worm and Pinkish boll worm affect the crop.
- A wide variety of agricultural and garden pesticides are available. A few derived from neem tobacco and chrysanthemum (Chamanthi) are less dangerous to other living organisms.
- A wide variety of inorganic and organic pesticides are commonly used D.D.T. (Dichloro diphenoxy Trichloro ethane) BHC (Benzene Hexa Chloride), Chlordane, Endrin, Aldrin, Endosulfan and Diazinon pesticides are usually dusted or sprayed on crops or put in the soil.
- But pesticides should not use unwisely. They get into the bodies of plants and animals in the soil and water. When these plants are eaten by animals like fish the pesticide get into their bodies.
- A bird that eat the fish might get a concentrated lethal dose.
- D.D.T. also accumulate in the egg shells, weakening them and making the shells break before hatching. It is observed D.D.T. is present in the milk of buffaloes and cows.
- In this way pesticides are passed down the food chain and accumulate in the bodies of higher animals including human beings causing sickness and sometimes death.
Question 17.
Venkatesh observed the irrigation method for paddy field. He wanted to follow the same practice for his Maize crop. What suggestions do you give him?
Answer:
- Paddy is grown as a Kharif or a Rabi crop. It requires high temperature of 22°C to 32°C and heavy rain fall. It is cultivated heavily in Kharif season.
- Maize is cultivated in both Kharif and Rabi seasons but heavily in Kharif season. This requires high temeprature (35°C) with moderate rainfall.
- So Venkatesh can follow the ame practice for his maize crop as the requirements of both the crops are almost same.
8th Class Biology 8th Lesson Production and Management of Food From Plants InText Questions and Answers
Question 1.
Look at the picture given below and write the constituents in it.
Answer:
Nitrogen (20%), Phosphorus (5%), Potash (10%)
Question 2.
Which manure is beneficial?
Answer:
Natural manure is beneficial.
Question 3.
Let us compare both, which manure is beneficial.
Chemical fertilizers | Natural fertilizers |
1. These are made up of inorganic salts. | 1. These are made by the decomposition of plants and animal (organic) wastes. |
2. These are prepared in factories. | 2. These are prepared in open places. |
3. No humus can be found. | 3. Deposits of humus layer is found in the soil. |
4. More amount of Nitrogen, Phosphorus and Potash deposits in the soil. | 4. Potash deposits in the soil. |
Observe the table carefully, discuss with your teacher and conclude which fertilizer is best to the farmers and why?
Answer:
Natural fertilizer is the best because this is made by the decomposition of plants and animal (organic) waste. Deposits of humus layer is found in the soil with less amount of Nitrogen, Phosphorus and potash deposits in the soil.
a) When do farmers irrigate the land?
Answer:
After applying manure farmers irrigate the land.
b) List out the water resources of your village.
Answer:
Wells, ponds, canals, tanks are the water resources.
c) Are they useful to your farmers?
Answer:
Yes. They are useful.
d) In what way the farmers of your village get water to the fields ?
Answer:
Farmers irrigate their fields either manually using bullocks or by using pumps.
Question 4.
What are the reasons for high production in Japan?
Answer:
Japan has cooler temperature.
Question 5.
What are the reasons for low production in India?
Answer:
High temperature and uncertainty of rainfall.
8th Class Biology 8th Lesson Production and Management of Food From Plants Activities
Activity – 1
Question 1.
CROPS IN INDIA:
Observe the following India map.
a) Are there many crops that are grow in most of the parts of our country? What are they?
Answer:
India is a unique position to grow almost every possible crop. It is the land of producing a variety of cereals like paddy, wheat, jowar, bajra, maize and ragi, pulses, spices, fruits, vegetables, oil seeds, fibre crops etc.
b) Why such crops are grown all over the country?
Answer:
India is an agricultural country and people derive their livelihood from agriculture. Agriculture is the back bone of Indian economy.
c) From the above map, which of them are grown in your village?
Answer:
Rice, pulses, banana, vegetables and leafy vegetables
a) Country: India
b) State: Andhra Pradesh
c) Your village: Khajipalem
d) How many days are required for getting the crop?
Answer:
Nearly 120 days.
e) Is time period for all crops are same?
Answer:
The time peirod for all the crops are not same. They are different from one crop to another.
f) Which crop needs more duration?
Answer:
Rice and Wheat.
Activity – 2
Question 2.
DURATION OF CROP:
a) Write the information in the table.
Name of the crop | Duration of the crop |
1. Paddy | 3 to 6 months |
2. Wheat | 110 to 120 days |
3. Jowar | 5 to 7 months |
4. Bajra | 100 to 120 days |
5. Maize | 100 days |
6. Raagi | May to Sept., Nov. and Dec. |
7. Pulses | 90 to 120 days |
8. Cotton | 165 days |
1. Example for long term crops:
Answer:
Jowar, red gram.
2. Example for short term crops:
Answer:
Pulses like green gram, black gram etc., and onions.
Activity – 3
Question 3.
WHERE DO CROPS ARE GROWN.
Discuss in groups and make a list of these things for the following table.
1. In which season do you find more varieties of vegetables in the market?
Answer:
Rainy season.
2. Generally farmers grow varieties of vegetables during rainy season. Can you guess the reason?
Answer:
In rainy season ponds, wells, rivers, ditches are pooled with water.
3. If we cultivate wheat in the month of the November what will happen?
Answer:
We get hot climate from February onwards. It is suitable for maturing the grains. That is the reason wheat is cultivated in the Rabi season only.
Activity – 4
Question 4.
PRODUCTION OF PADDY:
a) Go and collect the information through your nearest farmer and fill the following table.
a) In which season farmers get more benefits?
Answer:
Kharif season
b) Are there any other crops which are growing both Kharif and Rabi seasons?
Answer:
Paddy, wheat and maize
c) In which seasons farmers generally get good quality of seeds.
Answer:
Kharif and Rabi
d) The quantity of grains is higher in Kharif season than Rabi season. Do you agree this? Give your reasons.
Answer:
The climate, (the temperature, humidity with abundance of water supply) will be suitable in Kharif season
e) Do you know about third crop?
Answer:
The third crop season known as Zayad, grown in the months of April, May and June.
Activity – 5
Question 5.
SELECTION OF SEEDS:
Take some water in glass. Drop a fist of seeds in it. You cam observe some seeds will float on water. Collect those seeds and observe with hand lens and comparing with seeds sink under the water. Write your observations in the table.
a) What are the differences you observed in both seeds?
Answer:
Some seeds sank in water, some seeds floated.
b) Do you know why the floated seeds are light in weight?
Answer:
They are unhealthy seeds.
Activity – 6
Question 6.
GERMINATION AND SELECTION:
Show both the seeds in different pots and provide water uniformly, observe the growth of the plants in two pots and make a report.
1. Which seeds germinate well? Why?
Answer:
The seeds which are smooth and round germinate well because they are healthy seeds. Biology
2. Which seeds do not germinate properly? Why?
Answer:
The seeds which are wrinkled and rough do not germinate properly because they are unhealthy.
3. Were all the seeds were tested like this?
Answer:
The crop plant like Rice, wheat etc.
4. Do you know how the paddy seeds germinate?
Answer:
There are different stages in sprouting of the soaked rice seeds before it is planted.
5. Observe a sprout of paddy. Cam you say which part become root? Which part become shoot im the picture?
Answer:
Coleoptile become shoot and the part beneath the ground is root.
Activity – 7
Question 7.
SOWING METHODS
Collect information from the nearby farmers and fill in the table.
1. Why the seedlings are replanted at proper distance?
Answer:
They get water, mineral and sunlight equally when they are replanted at proper distance.
2. Do all the crops grow when replanted? Why not?
Answer:
Mostly all plants will grow.
Activity – 8
Question 8.
CROPS AND DISEASES:
Form a group with 4 to 5 of your classmates, visit nearby field, discuss with farmers about diseases effected by, and how to control them. If you do not know the name of the disease, write its local name or its characters.
1. Do all the farmers use the same pesticides for the same crop?
Answer:
For different crops different pesticides are used.
2. Is there any disease that you find in all fields?
Answer:
No
3. Where do they buy pesticides?
Answer:
From government and private agencies.
4. What are the appliances that they use to spray pesticides?
Answer:
Sprayer or dusters.
5. Did you find any other living organisms dying along with pests due to pesticides ? What are they ?
Answer:
Yes. Caterpillars, sparrows etc.
Activity – 9
Question 9.
IDENTIFICATION OF PESTS:
Observe the plants in a nearby field or in your school garden. Closely observe the leaves and stems to collect the following information. If the character is present put a ‘S’ mark and if there is no character put ‘X’ mark.
Name of the plant/crop : Rice (Blast of Rice)
Place: Prakasam
a. Do all the leaves of plant have spots?
Answer:
Yes, all the leaves of plant have spots.
b. Draw the leaf with these spots.
Answer:
c. What is your reason for the leaves which have cutting edges?
Answer:
Eaten by grasshoppers.
d. Do you find any twilted leaves with insects? How are they?
Answer:
Infection occurs on leaf sheaths.
e. Are the scars on the stems is same as spots on leaves?
Answer:
Yes, the scars on the stems is same as spots on leaves.
f. Collect powdery substance of the spots on leaves and observe under microscope. Write down your observations.
Answer:
Fungus produce small spores known as conidia.
Activity – 10
Question 10.
PEST CONTROLING PRACTICES:
In your village farmers control pests by using different pesticides and insecticides for different crops. For this they use different practices. Ask your elders the names of pesticides that they use in the following pest controlling practices.
Answer:
- Spraying: Endrin, Diethane, M-45, Eldrine.
- Dusting: Aldrin, D.D.T.
- Put in the soil: Zinc, Sulphur, Phosphorous, fluorine
- Burning and picking are also the practices where they use these: Sugarcane, citrus
- Bio pesticides: Neem water
Observe the following pest controlling practices
a. Which of the above practices is good?
Answer:
A farmer remove the affected leaves from the plant and burnt them.
b. Why do you think so?
Answer:
By burning the affected leaves the pests will be controlled.
c. Why did the farmer use two pesticides at a time?
Answer:
At the first time the pests will be controlled by spraying pesticide, but if we use unwisely, pests become resistant to the pesticides.
d. What will we do to solve the problem?
Answer:
Pesticides will be used as per the requirement for the disease.
e. Farmers add manure to the soil.
What they used to add?
Answer:
They used to add nutrients to the soil.
f. Have you a compost pit in your school / house?
Answer:
Yes, there is a compost pit in our school. All the waste materials like dry leaves, fruits peel etc. will dump into the pit.
Activity – 11
Question 11.
WHEN SHOULD FARMERS IRRIGATE THE HELD?
Consult to the farmers and fill the table with the information to how and when they provide water to various crops.
a. Are all the crops provided with equal amount of water?
Answer:
No. Irrigation should be done according to nature of the soil and the type of crop to be grown.
b. Why do farmers provide more water to the summer crops?
Answer:
Summer season is the hottest climate so the crops which grow in summer requires high quantity of water.
Weedling:
a. Why should they (weeds) be removed?
Answer:
The weeds compet with the primary crops for nutrients, water and light because of these plants crop plants may not grow properly. So they should be removed.
Question 12.
How sprinklers and drip system are used and write down their merits and demerits.
Answer:
When the availability of water is poor, drip irrigation system is used. In this the water reaches the plant drop by drop through sprinklers. So that water comes out from the sprinklers wetting exactly the place of the roots of the plant.
Advantages:
- Maximum use of available water.
- No water being available to weeds.
- Maximum crop yield.
- Efficiency use of fertilizers.
- Less weed growth.
- Low labour and low operation cost.
- No soil erosion.
- Improved infiltration in soil with low in take.
Disadvantages:
- Sensitivity to clogging.
- Moisture distribution problem.
- Salinity hazards
- High cost compared to furrow.
- High skills is required for design, install and operation.
Activity – 12
Question 13.
Ask your nearby nursery and know the weeds that grow in different crops. Make a table in your notebook.
Name of the plant | WEEDS |
1) Paddy | Garika, Wanza, Varipilla Gaddi, Sukha Bhogi, Dharaka, Buradha, Thunga |
2) Vegetable crop | Gunugu, Gaddi Chamanthi, Jeeluga |
3) Cotton fields | Puli chinta |
4) Mirchi | Puli chinta |
5) Tobacco | Pogaku Malle |
Harvesting of paddy:
a. If the paddy is not dried well enough. What will happen?
Answer:
If moisture is there in paddy grains it helps to develop moulds (fungi). Such grains neither germinate nor suitable to eat.
b. Where do farmers harvest the crops in your village ?
Answer:
Farmers generally used to harvest by using traditional methods.
c. Is harvesting same for all crops?
Answer:
Yes.
Activity – 13
Question 14.
Find out the methods of harvesting in and around our village and fill the table.
Answer: