AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production

Andhra Pradesh BIEAP AP Inter 2nd Year Botany Study Material 13th Lesson Strategies for Enhancement in Food Production Textbook Questions and Answers.

AP Inter 2nd Year Botany Study Material 13th Lesson Strategies for Enhancement in Food Production

Very Short Answer Questions

Question 1.
What is meant by “hidden hunger”?
Answer:
It is a chronic lack of vitamins and minerals that often has no visible warning signs. It leads to mental impairment, poor health, and productivity or even death.

Question 2.
Name two Semi-Dwarf varieties of rice developed in India.
Answer:
Jaya and Ratna.

Question 3.
Give two examples of wheat varieties introduced in India, which are high-yielding and disease resistant.
Answer:
Sonalika and Kalyan Sona.

Question 4.
Give two examples of fungi used in SCP production.
Answer:
Candida utilis (Torula yeast), Saccharomyces cerevisiae (Baker’s yeast), Chaetomium cellulolyticum.

Question 5.
Which two species bf sugarcane were crossed for better yield?
Answer:
Saccharum barberi’and Saccharum officinarum were crossed for better yield, high sugar etc.

AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production

Question 6.
Define totipotency and explant.
Answer:
Totipotency:
The ability of a cell (or) an explant to regenerate into a complete plant is called totipotency.

Explant:
It is a part of a plant taken out and grown in a test tube under sterile conditions in special nutrient media.

Question 7.
Define micropropagation and somaclones.
Answer:
Micropropagation:
The production of large number of plants in a very short time and limited space is known as micropropagation.

Somaclones :
Plants grown through tissue culture which are genetically identical with the original plant are called somaclones.

Question 8.
What is meant by germplasm collection?
Answer:
The entire collection of plants/seeds, having all the diverse alleles for all genes in a given crop is called germplasm collection.

Question 9.
What is meant by Biofortification?
Answer:
Development of crops with higher levels of vitamins and minerals or higher protein and healthier fats to improve public health.

Question 10.
Which part of the plant is best suited for making virus-free plants and why?
Answer:
Meristem. Here the cells are in dividing state.

Short Answer Questions

Question 1.
Give few examples of biofortified crops. What benefits do they offer to the society?
Answer:
1) Wheat variety, Atlas 66, having a high protein content.
2) Rice variety, Golden Rice – β carotene containing variety.
AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production 1
6) Broad, lablab, French and garden peas – Protein enriched beans.

Benefits :

  1. It aims at breeding crops with higher levels of vitamins and minerals.
  2. Higher protein and healthier fats to improve public health.

AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production

Question 2.
Write a short note on SCR
Answer:
Dried biomass of a single cell species of microbes that can be used as proteins are called single cell protein.

  1. SCP is an alternative sources of proteins for animal and human nutrition.
  2. Microbes like algae, fungi and bacteria are used in SCP production.
  3. Spirulina maxima, chlorella pyrenoidosa and scenedesmos acutus are the examples of Algal SCP.
  4. Spirulina can be grown easily on materials like waste water from potato processing plants, straw, molasses and animal manure and can serve as food which is rich in protein, minerals, fats, carbohydrates & vitamins.
  5. SCP utilization can reduces environmental pollution.
  6. It is possible to produce large amount of protein in short period of time. For example 250 kg cow produces 200 g of protein per day. In the same period 250 g of a protein produces by methylophilus methylotrophus bacterial SCP.
  7. Candida utilis, Bakers yeast, chaetomium cellulolyticum are good examples of Fungal SCP.

Long Answer Questions

Question 1.
You are a Botanist working in the area of plant breeding. Describe the various steps that you will undertake to release a new variety.
Answer:
The main steps in breeding a new genetic variety of a crop are :

1) Collection of Variability:
Genetic variability is the root of any breeding programme. Collection and preservation of all the different wild varieties, species and relatives of cultivated species is a prerequisite for effective exploitation of natural genes available in the populations.

The entire collection having all the diverse alleles for all genes in a given crop is called Germplasm collection.

2) Evaluation and selection of parents :
The germplasm is evaluated so as to identify plants with desirable characters. The selected plants are multiplied and are used. Purelines are created wherever desirable.

3) Cross Hybridisation among the selected parents :
After emasculation (Removal of Anthers from bisexual flower of a fpmale parent) the female flowers are enclosed in a polythene bag to prevent undesired cross pollination.

pollen grains are collected from the male parent with the help of a brush and are transferred to the surface of the stigma and thus cross pollination is affected artificially.

4) Selection and Testing of superior recombinants :
It involves selecting among the progeny of hybrids, those plants that have the desired character combination. The selection process requires careful scientific evaluation of the progeny. Due to this, plants that are superior to both the parents are obtained. These are self pollinated for several generations till they reach a homozygosity.

5) Testing, release and commercialisation of new characters :
The newly selected lines are evaluated for their yield and other traits of quality, disease resistance etc. It is done by growing these in research fields and recording their performance under ideal fertilizer application, irrigation and other crop management practices. It is followed by testing the materials in farmers fields for at least 3 growing seasons at several places in the country, in all agroclimatic zones. Finally they are distributed to farmers as a new variety.

AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production

Question 2.
Describe the tissue culture technique and what are the advantages of tissue culture over conventional method of plant breeding in crop improvement programmes?
Answer:
Tissue culture Technique : It involves
a) Preparation of Nutrient medium :
The nutrient medium is a mixture of various essential nutrients, aminoacids, vitamins and carbohydrates. These are mixed in distilled water and PH is adjusted to 5.6 to 6.0. Growth regulators like auxins, cytokinins are added to the medium. The nutrient medium is poured in glass vessels and closed tightly with cotton plugs before sterilizing them in an autoclave.

b) Sterilisation :
The nutrient medium is rich in nutrients and therefore attracts the growth of microorganisms. The culture medium is auto claved for 15 mins, at 121°c or 15 pounds of pressure to make aseptic.

c) Preparation of explant:
Any living part of plant can be used as explant. The explants must be cleaned with liquid detergent and in running water and surface sterilised with sodium hypo chlorite and rinsed with distilled water.

d) Inoculation of explants :
The transfer of explants on to the sterilized nutrient medium is called inoculation. It is carried out under sterilized conditions.

e) Incubation:
The culture vessels with inoculated explants are incubated in a culture room under controlled temperature, optimum light and humidity. The cultures are incubated for 3 – 4 weeks, the cells of the explant divide arid redivide, producing a mass of tissue called callus. The callus is transferred to another medium containing growth regulators to initiate the formation of roots and leafy shoot (organogenesis). Sometimes embryo like structures develop directly from the callus which are referred as somatic embryos. These can be encapsulated with sodium alginate to form synthetic or artificial seeds.

f) Acclamatization and transfer to pots :
The plants produced through tissue culture are washed gently and are planted in pots kept in glass house for 1-2 weeks. Finally they are transferred to field.

Advantages:

  1. The production of exact copies of plants that produce particularly good flowers, fruits or have other desirable traits.
  2. To quickly produce mature plants.
  3. The production of multiples of plants in the absence of seeds or necessary pollinators to produce seeds.
  4. The regeneration of whole plants froih plant cells that have been genetically modified.
  5. The production of plants from seeds that otherwise have very low chances of germinating and growing i.e., orchids and nepenthes.
  6. To clean particular plants of viral and other infections and to quickly multiply these plants as cleaned stock for Horticulture and Agriculture.

Intext Questions

Question 1.
Describe in brief, various steps involved in plant breeding.
Answer:
The main steps in breeding a’new genetic variety of a crop are :
1) Collection of Variability: Genetic variability is the root of any breeding programme . Collection and preservation of all the different wild varieties, species and relatives of cultivated species is a prerequisite for effective exploitation of natural genes available in the populations.

The entire collection haring all the diverse alleles for all genes in a given crop is called Germplasm collection.

2) Evaluation and selection of parents :
The germplasm is evaluated so as to identify plants with desirable characters. The selected plants are multiplied and are used. Purelines are created wherever desirable.

3) Cross Hybridisation among the selected parents :
After emasculation (Removal of Anthers from bisexual flower of a female parent) the female flowers are enclosed in a polythene bag to prevent uridesired cross pollination.

pollen grains are collected from the male parent with the help of a brush and are transferred to the surface of the stigma and thus cross pollination is affected artificially.

4) Selection and Testing of superior recombinants :
It involves selecting among the progeny of hybrids, those plants that have the desired character combination. The selection process requires careful scientific evaluation of the progeny. Due to this, plants that are superior to both the parents are obtained. These are self pollinated for several generations till they reach a homozygosity.

5) Testing, release and commercialisation of new characters :
The newly selected lines are evaluated for their yield and other traits of quality, .disease resistance etc. It is done by growing these in research fields and recording their performance under ideal fertilizer application, irrigation and other crop management practices. It is followed by testing the materials in farmers fields for at least 3 growing seasons at several places in the country, in all agroclimatic zones. Finally they are distributed to farmers as a new variety.

Question 2.
What is the major advantage of producing plants by micropropagation?
Answer:
Plants produced are genetically identical to the original source of plant.

Question 3.
Find out what are the various components of the medium used for propagation of an explant in vitro?
Answer:
Sucrose, Inorganic salts, vitamins, amino acids, growth regultaors like Auxins, Cytokinins, water, agar-agar.

Question 4.
Name any five hybrid varieties of crop plants which have been developed in India.
Answer:
Rice – Semidwarf varities – Jaya, Ratna.

Question 5.
The term ‘desirable trait’ can mean different things for different plants. Justify the statement with suitable examples.
Answer:
Different plants have different qualities in expressing desirable traits/characters. Eg.: Bacillus thermogenesis is used to kill other insect larvae acting as pesticide is a desirable trait. Another examples are Bt Cotton, Bt Com, rice, tomato, potato all have good qualities in increasing food production.

Question 6.
Is there any relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments?
Answer:
Yes, cultured tissue must certain competent cells or cells capable of reasoning competance (dedifferentiation).
Ex : an Explant → dedifferentiation → allay redifferentiation (whole plant) = cellular Totipotency.

Question 7.
“Give me a living cell of any plant and I will give you a thousand plants of the same type” is this only a slogan or is it scientifically possible? Write your comments and Justify them.
Answer:
It is possible to produce large number of plants from a living cell with in a short period is called micropropagation. Because each living cell of any plant has the capacity to develop into a new plant called totipotency. Based on this principle. It is possible to produce several plants which are identical to parents.

AP Inter 2nd Year Botany Study Material Chapter 13 Strategies for Enhancement in Food Production

Question 8.
What are the physical barriers of a cell in the protoplast fusion experiment? How are the barriers overcome?
Answer:
Cell wall is the physical barrier of cell. To Isolate protoplast from the cells, the cells are to be treated with cellulages and pectinages to break the cell walls. Then protoplasts are taken and are fused with the help of polyethylene Glycol to obtain a hybrid plants.