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Strategies For Enhancement In Food Production

Class 12th Biology NCERT Exemplar Solution
Multiple Choice Questions
  1. The chances of contacting bird flu from a properly cooked (above 100°C) chicken and egg…
  2. A group of animals which are related by descent and share many similarities are referred…
  3. Inbreeding is carried out in animal husbandry because it:
  4. Sonalika and Kalyan Sona are varieties of:
  5. Which one of the following is not a fungal disease?
  6. In virus-infected plants the meristematic tissues in both apical and axillary buds are…
  7. Several South Indian states raise 2-3 crops of rice annually. The agronomic feature that…
  8. Which one of the following combination would a sugarcane farmer look for in the sugarcane…
  9. Fungicides and antibiotics are chemicals that:
  10. Use of certain chemicals and radiation to change the base sequences of genes of crop…
  11. The scientific process by which crop plants are enriched with certain desirable nutrients…
  12. The term ‘totipotency’ refers to the capacity of a:
  13. Given below are a few statements regarding somatic hybridization. Choose the correct…
  14. An explant is:
  15. The biggest constraint of plant breeding is:
  16. Lysine and tryptophan are:
  17. Micro-propagation is:
  18. Protoplast is:
  19. To isolate protoplast, one needs:
  20. Which one of the following is a marine fish:
  21. Which one of the following products of apiculture is used in cosmetics and polishes:…
  22. More than 70 per cent of livestock population is found in:
  23. The agriculture sector of India employs about:
  24. 33 percent of India’s Gross Domestic Product comes from
  25. A collection of all the alleles of all the genes of a crop plant is called:…
Very Short Answer Type
  1. Millions of chicken were killed in West Bengal, Assam, Orissa and Maharashtra recently.…
  2. Can gamma rays used for crop improvement programmes prove to be harmful for health?…
  3. In animal husbandry, if two closely related animals are mated for a few generations, it…
  4. In the area of plant breeding, it is important not only to preserve the seeds of the…
  5. Name a man-made cereal? Trace how it was developed and where is it used?…
  6. Fill in the blanks
  7. A few statements are given below followed by a set of terms in a box. Pick the correct…
  8. What is meant by ‘hidden hunger’?
  9. Why are plants obtained by protoplast culture called somatic hybrids?…
  10. What is protoplast fusion?
  11. Why is it easier to culture meristems compared to permanent tissues?…
  12. Why are proteins synthesised from Spirulina called single cell proteins?…
  13. A person who is allergic to pulses was advised to take a capsule of Spirulina daily. Give…
  14. What is aquaculture? Give example of an animal that can be multiplied by aquaculture.…
  15. What are the duties of a veterinary doctor in management of a poultry farm?…
  16. Would it be wrong to call plants obtained through micro-propagation as ‘clones’? Comment.…
  17. How is a somatic hybrid different from a hybrid?
  18. What is emasculation? Why and when is it done?
  19. Discuss the two main limitations of plant hybridization programme.…
  20. Interspecific crosses are rare in nature and intergeneric crosses almost unknown. Why?…
  21. Differentiate between pisciculture and aquaculture.
  22. Give two important contributions of Dr. M. S. Swaminathan.
  23. The term ‘desirable trait’ can mean different things for different plants. Justify the…
Short Answer Type
  1. You are planning to set up a Dairy Farm. Describe the various aspects you would consider…
  2. It is said, that diseases are spreading faster due to globalisation and increased movement…
  3. Explain the concept of the Blue Revolution.
  4. A farmer was facing the problem of low yield from his farm. He was advised to keep a…
  5. Life style diseases are increasing alarmingly in India. We are also dealing with large…
  6. How can we improve the success rate of fertilisation during artificial insemination in…
  7. What is meant by germplasm collection? What are its benefits?
  8. Name the improved characteristics of wheat that helped India to achieve green revolution.…
  9. Suggest some of the features of plants that will prevent insect and pest infestation.…
  10. It is easier to culture plant cells in vitro as compared to animal cells. Why? +…
  11. The culture medium (nutrient medium) can be referred to as a ‘highly enriched laboratory…
  12. Is there any relationship between dedifferentiation and the higher degree of success…
  13. “Give me a living cell of any plant and I will give you a thousand plants of the same…
  14. What is the difference between a breed and a species? Give an example for each category.…
  15. Plants raised through tissue cultures are clones of the ‘parent’ plant. Discuss the…
  16. Discuss the importance of testing of new plant varieties in a geographically vast country…
  17. Define the term ‘stress’ for plants. Discuss briefly the two types of stress encountered…
  18. Discuss natural selection and artificial selection. What are the implications of the…
  19. Discuss briefly how pure lines are created in animal husbandry.
  20. What are the physical barriers of a cell in the protoplast fusion experiment? How are the…
  21. Give few examples of biofortified crops. What benefits do they offer to the society?…
Long Answer Type
  1. You are a Botanist working in the area of plant breeding. Describe the various steps that…
  2. (a) The shift from grain to meat diets creates more demands for cereals. Why?(b) A 250 kg…
  3. What are the advantages of tissue culture methods over conventional method of plant…
  4. ‘Modern methods of breeding animals and plants can alleviate the global food shortage’.…
  5. Does apiculture offer multiple advantages to farmers? List its advantages if it is located…
  6. (a) Mutations are beneficial for plant breeding. Taking an example, justify the statement.…
  7. Discuss how the property of plant cell totipotency has been utilised for plant propagation…
  8. What are three options to increase food production? Discuss each giving the salient…

Multiple Choice Questions
Question 1.

The chances of contacting bird flu from a properly cooked (above 100°C) chicken and egg are:
A. very high

B. high

C. moderate

D. negligible


Answer:

Bird flu is caused by avian influenza. The influenza can be found inside or on the surface of the egg. Heat is known to deactivate the pathogens and cooking at such a high temperature of 100°C and above helps in killing the strains of avian influenza.


Hence, the chances of contacting bird flu from a properly cooked (above 100°C) chicken and egg are negligible.


Question 2.

A group of animals which are related by descent and share many similarities are referred to as:
A. breed

B. race

C. variety

D. species


Answer:

Breed is a group of animals that have similar appearance and behaviour and can be easily distinguished from other organisms. Example: American saddlebred and Arabian breed of horses etc.


Race is a genetically distinct population of individuals within the same species. Example: white race, black race etc in Homo sapiens.


Variety is a taxonomic rank below species. In variety the member of the same species have very minor difference. Example: white, red, pink etc variety of roses.


Species is a group of closely related organism (individuals) that are similar and are capable of interbreeding. Example: sapiens and erectus species of genus Homo.


Hence, due to above reasons the answer is breed.


Question 3.

Inbreeding is carried out in animal husbandry because it:
A. increases vigour

B. improves the breed

C. increases heterozygosity

D. increases homozygosity


Answer:

• Inbreeding is defined as the mating of more closely related individual within the same breed for 4-5 generation.


• Individuals produced by inbreeding are exactly similar to their parents and hence are considered as purelines.


• Homozygosity is referred to as condition in which the animal has identical alleles in a pair.


• Inbreeding results in transfer of same alleles generation to generation, hence, causing homozygosity.


• Inbreeding results in the production of purelines, thus there is no chances of increased vigour.


• Same alleles throughout many generations also do not guarantee improved breed.


• Same alleles are passed in inbreeding so heterozygosity does not increase.


• Inbreeding produces pureline, hence increasing homozygosity.


Hence, Inbreeding is carried out in animal husbandry because it increases homozygosity.


Question 4.

Sonalika and Kalyan Sona are varieties of:
A. wheat

B. rice

C. millet

D. tobacco


Answer:

• Sonalika and kalyan sona are the high yielding and disease resistant varieties of wheat which were introduced all over the wheat growing belt of India in 1963.


• Some examples of rice variety are Jaya, Ratna etc.


• Examples of millet variety are hybrid maize, jowar, bajra etc.


• Example of tobacco variety are bidi tobacco, cigar filled tobacco etc


Hence, kalyan sona and sonalika are varieties of wheat.


Question 5.

Which one of the following is not a fungal disease?
A. Rust of wheat

B. Smut of Bajra

C. Black rot of crucifers

D. Red rot of sugarcane


Answer:

• Rust of wheat is caused by Puccinia triticina which is a fungi.


• Smut of bajra is caused by fungus Tolyposporium penicillariae.


• Black rot of crucifers is caused by Xanthomonas campestris. It is a bacteria.


• Red rot of sugarcane is caused by fungus Colletotrichum falcatum.


Hence, black rot of crucifer is not a fungal disease.


Question 6.

In virus-infected plants the meristematic tissues in both apical and axillary buds are free of virus because:
A. the dividing cells are virus resistant

B. meristems have anti viral compounds

C. the cell division of meristems are faster than the rate of viral multiplication

D. Viruses cannot multiply within meristem cell (s).


Answer:

The mersistems does not have antiviral property nor the dividing cells are virus resistant. Viruses can easily multiply with meristems cells but with slower rate.


Hence, in virus-infected plants the meristematic tissues in both apical and axillary buds are free of virus because the cell division of meristems are faster than the rate of viral multiplication.


Hence, (c) is the correct option.


Question 7.

Several South Indian states raise 2-3 crops of rice annually. The agronomic feature that makes this possible is because of
A. shorter rice plant

B. better irrigation facilities

C. early yielding rice variety

D. disease resistant rice variety.


Answer:

The ability of raising 2-3 crops of rice annually can only be possible when the crops undergo early maturity and gives yield early.


Hence, (c) is the correct option.


Question 8.

Which one of the following combination would a sugarcane farmer look for in the sugarcane crop?
A. Thick stem, long internodes, high sugar content and disease resistant

B. Thick stem, high sugar content and profuse flowering

C. Thick stem, short internodes, high sugar content, disease resistant

D. Thick stem, low sugar, conten, disease resistant


Answer:

Thick stem gives more strength to the plant to be able to stand properly for long time, high sugar content is necessary for good quality of crop. The disease resistant variety is useful as it prevents the growth of disease.


Hence, (a) is the correct option.


Question 9.

Fungicides and antibiotics are chemicals that:
A. enhance yield and disease resistance

B. kill pathogenic fungi and bacteria, respectively

C. kill all pathogenic microbes

D. kill pathogenic bacteria and fungi respectively.


Answer:

Fungicides are chemicals that are used to kill the fungi and antibiotics are the chemical used to kill the bacteria.


Hence, (b) is the correct option.


Question 10.

Use of certain chemicals and radiation to change the base sequences of genes of crop plants is termed:
A. recombinant DNA technology

B. transgenic mechanism

C. mutation breeding

D. gene therapy.


Answer:

Recombinant DNA Technology is the process by which the desirable DNA is formed using various techniques.


Transgenic mechanism is the induction of desirable DNA into the host.


Mutation breeding is the method of artificial breeding.


Gene therapy is a technique by which the disease is treated or prevented using genes.


Hence, (c) is the correct option.


Question 11.

The scientific process by which crop plants are enriched with certain desirable nutrients is called:
A. crop protection

B. breeding

C. bio-fortification

D. bio-remediation.


Answer:

Crop protection is the method of protecting the crops from physical and anatomical damage.


Breeding refers to the mating of two organisms from same or different breed.


Bio-fortification is a way to increase nutrient quantity in the food.


Bio-remediation is the process to treat contaminated media.


Hence, (c) is the correct option.


Question 12.

The term ‘totipotency’ refers to the capacity of a:
A. cell to generate whole plant

B. bud to generate whole plant

C. seed to germinate

D. cell to enlarge in size.


Answer:

Totipotency is the ability of the cell (explants) to generate the whole plant when kept in suitable conditions in vitro.


Hence, (a) is the correct option.


Question 13.

Given below are a few statements regarding somatic hybridization. Choose the correct statements.

(i) protoplasts of different cells of the same plant are fused

(ii) protoplasts from cells of different species can be fused

(iii) treatment of cells with cellulase and pectinase is mandatory

(iv) the hybrid protoplast contains characters of only one parental protoplast.

A. (i) and (iii)

B. (i) and (ii)

C. (i) and (iv)

D. (ii) and (iii)


Answer:

In somatic hybridisation, the cell is treated with pectinase and cellulose for the breakdown of cell wall, so that isolation of protoplast can take place. The protoplasts of two different species are fused and the offspring has the characters of both parents.


Hence, (d) is the correct option.


Question 14.

An explant is:
A. dead plant

B. part of the plant

C. part of the plant used in tissue culture

D. part of the plant that expresses a specific gene.


Answer:

The base of the tissue culture is formed by the explants. An explant is a part of plant that has the ability of generating whole plant if kept in culture medium and desirable conditions.


Hence, (c) is the correct option.


Question 15.

The biggest constraint of plant breeding is:
A. availability of desirable gene in the crop and its wild relatives

B. infrastructure

C. trained manpower

D. transfer of genes from unrelated sources.


Answer:

The availability of desirable gene is very difficult because first the desirable and profitable genes are not found and if they are found then they are linked with undesirable gene whose extraction becomes very difficult.


Infrastructure and trained manpower is very common and can be found easily with money.


Many new technologies are developed through which the transfer of genes is possible.


Hence, (a) is the correct option.


Question 16.

Lysine and tryptophan are:
A. proteins

B. non-essential amino acids

C. essential amino acids

D. aromatic amino acids.


Answer:

Proteins are made of amino acids. Lysine and tryptophan are amino acids.


Non essential amino acids are present in the body and are not supplied with the diet.


Lysine and tryptophan are present in very small amount in the body and when they are needed by the body they are supplied in the diet. Hence, they are known as essential amino acids.


Tryptophan is an aromatic amino acid but lysine has a straight chain.


Hence, (c) is the correct option.


Question 17.

Micro-propagation is:
A. propagation of microbes in vitro

B. propagation of plants in vitro

C. propagation of cells in vitro

D. growing plants on smaller scale.


Answer:

An explant when placed in culture medium is capable of producing the whole plant. This is known as totipotency. Using this property, a large number of plants can be produced. This is known as micro propagation.


Hence, (b) is the correct option.


Question 18.

Protoplast is:
A. another name for protoplasm

B. an animal cell

C. a plant cell without a cell wall

D. a plant cell.


Answer:

Protoplasm is the cell content (protoplasm = cytoplasm + nucleus). Protoplast is a plant cell without cell. All the content cell membrane, nucleus and cytoplasm forms the protoplast.


Hence, (c) is the correct option.


Question 19.

To isolate protoplast, one needs:
A. pectinase

B. cellulase

C. both pectinase and cellulase

D. chitinase.


Answer:

The cell wall of plants is chemically made of cellulose and pectin. In order to digest the cell wall to isolate protoplast, the cell wall digesting enzymes are used. Pectinase breaks down pectin and cellulose breaks down cellulose.


Hence, (c) is the correct option.


Question 20.

Which one of the following is a marine fish:
A. Rohu

B. Hilsa

C. Catla

D. Common Carp.


Answer:

Rohu, Catla and common carp lives in fresh water. Hence, (b) is the correct option.


Question 21.

Which one of the following products of apiculture is used in cosmetics and polishes:
A. honey

B. propolis

C. wax

D. Royal jelly


Answer:

Honey is used as a food item. Propolis is resin like material and is used for its antioxidant and anti-inflammatory properties. Bee wax is used in industry. Royal jelly is the extra food of the queen bee and is a potent antioxidant and very commonly used in cosmetics and polishes.


Hence, (d) is the correct option.


Question 22.

More than 70 per cent of livestock population is found in:
A. Denmark

B. India

C. China

D. India and China.


Answer:

It was estimated by the recent research that more than 70% of the live stock population is found in India and China.


Hence, (d) is the correct answer.


Question 23.

The agriculture sector of India employs about:
A. 50 per cent of the population

B. 70 per cent of the population

C. 30 per cent of the population

D. 60 per cent of the population.


Answer:

Agriculture is the most important sector of Indian economy and according to the current research it employs about 62 per cent of the population.


Hence (d) is the correct answer.


Question 24.

33 percent of India’s Gross Domestic Product comes from
A. Industry

B. Agriculture

C. Export

D. Small-scale cottage industries.


Answer:

GDP from Industry in India is 7.39%.


In India about 60% people are occupied in doing farming as a result 33% of India’s gross domestic product comes from agriculture.


GDP from export is 19.31%.


GDP from small scale cottage industries is very limited.


Hence (b) is correct answer.


Question 25.

A collection of all the alleles of all the genes of a crop plant is called:
A. germplasm collection

B. protoplasm collection

C. herbarium

D. somaclonal collection.


Answer:

A germplasm collection is the collection of all the variety of alleles for all genes in a given crop.


Collection of protoplast is known as protoplasm collection.


A herbarium is a collection of dried leaves of plants for the purpose of identification.


Somaclonal collection is the collection of clones formed by the process of somatic hybridisation.


Hence (a) is the correct answer.



Very Short Answer Type
Question 1.

Millions of chicken were killed in West Bengal, Assam, Orissa and Maharashtra recently. What was the reason?


Answer:

Recently the chickens of the states of West Bengal, Assam, Orissa and Maharashtra were infected with the virus that is responsible for the bird flu.

Hence, in order to prevent the flu from further spreading in other areas, the chickens in these states were killed.



Question 2.

Can gamma rays used for crop improvement programmes prove to be harmful for health? Discuss.


Answer:

The crops are subjected to the gamma rays in a closed area. The rays then cause mutations in the crops and only the crop with desired and useful mutations are used for further growth. Also, the humans are not in direct contact with the rays.

Hence, gamma rays used for crop improvement programmes are not harmful for health



Question 3.

In animal husbandry, if two closely related animals are mated for a few generations, it results in loss of fertility and vigour. Why is this so?


Answer:

When two closely related animals are mated, it is known as inbreeding. Inbreeding results in homozygosity in which the pair of alleles has similar alleles. Continued inbreeding causes inbreeding depression because due to homozygosity there is accumulation of recessive genes in the animals.

The accumulation of recessive genes results in loss of fertility and vigour. Hence, in animal husbandry, if two closely related animals are mated for a few generations, it results in loss of fertility and vigour.



Question 4.

In the area of plant breeding, it is important not only to preserve the seeds of the variety being cultivated, but also to preserve all its wild relatives. Explain with a suitable example.


Answer:

The different varieties of plant be it cultivated or wild relatives have many important and advantageous genes.

For example: The wild varieties of cultivated plants although have very low yield but they have various resistant characters (genes) that can be introduced in other high yielding plants.


Hence, in order to store the resistant genes, it is important not only to preserve the seeds of the variety being cultivated, but also to preserve all its wild relatives.



Question 5.

Name a man-made cereal? Trace how it was developed and where is it used?


Answer:

The man made cereal is Triticale.

Development of Triticale:


This man made cereal is a hybrid and was developed by crossing rye with wheat.


Its name indicates its origin. Triti from Triticum(wheat) and ale from Secale(rye). In the hybrid the wheat is used as the female parent and the rye is used as male parent that is the pollen donar.


Mostly, the diploid rye cereal having 14 chromosomes was crossed by a tetraploid wheat parent (4n=28) resulting in the hexaploid offspring.


Uses:


This cereal is used as fodder. The fodder is the food for animals.



Question 6.

Fill in the blanks




Answer:

I: Cellulases catalyse is the enzyme that breaks down the plant cell wall as it is majorly made up of cellulose.


After digestion or breakdown of cell wall of tomato and potato, the fusion of protoplast of potato and tomato cell takes place.


II: Somatic hybridisation is the name of the process. The process is named so because in this the hybrids are formed from the cells other than the reproductive cells.


***note: somatic cells are cell of organism other than the reproductive cell.***


III: The plant formed by the fusion of tomato and potato cell is generally termed as Pomato/Topato.


The name of the plant is formed by joining the tomato and potato.


***note: unfortunately this hybrid plant does not have all the desired character to be used commercially.


IV: Somatic hybrid is the term used to denote such plants.


These plants are formed by the fusion of somatic cells of two different plants and hence they are named so.



Question 7.

A few statements are given below followed by a set of terms in a box. Pick the correct term and write it against the appropriate statement

a. Mating of closely related individuals within the same breed

b. Mating of animals of same breed but having no common ancestors on either side for 4-6 generations

c. Mating of animals of two different species

d. Breeding of animals belonging to different breeds

(i) Cross breeding, (ii) Inter-specific hybridization, (iii) Out breeding, (iv) Out crossing, (v) Inbreeding


Answer:

a. Inbreeding


Explanation: When the mating takes place between the more closely related individuals of same breed for 4-5 generations, it is termed as inbreeding.


b. Out crossing


Explanation: There is another case in which the mating takes place between the individuals of same breed but these individuals do not have any common ancestor for 4-5 generations on the either side. The offspring (progeny) of such mating is called an out cross.


c. Inter-specific breeding


Explanation: When the mating of animals of two different species takes place, it is known as inter-specific breeding. In such breeding the male and female animals of two different related species are mated. Sometimes the hybridization produces offspring with desirable characters and is economically useful. But this is very rare in nature.


d. Cross breeding


Explanation: When the mating takes place between the superior males of one breed and the superior female of other breed, it is known cross breeding. In this two different breeds are involved and in such way that the desirable characters of two breeds are fused.


***note: out-cross, cross-breeding and inter specific breeding together comes under out breeding.***



Question 8.

What is meant by ‘hidden hunger’?


Answer:

Hidden hunger means the deficiency of certain nutrients in the body in which no specific symptoms are seen.

Hidden hunger occurs when the food do not have required amount of nutrient and hence there is a deficiency of micronutrients such as vitamins and minerals. In hidden hunger the person suffering may not be even aware of it.



Question 9.

Why are plants obtained by protoplast culture called somatic hybrids?


Answer:

Plants obtained by protoplast culture are called somatic hybrids because these plants are formed by the fusion of protoplasts of two different plant varieties, each having desirable characters.

Also the new plant formed is not by the fusion of germ cells but protoplasts, hence the name somatic.



Question 10.

What is protoplast fusion?


Answer:

The two plant varieties of plants with desirable characters are selected and their cells are extracted, the cell walls of the cells are broken down by protein digesting enzyme and the naked protoplast is fused under laboratory conditions. This is known as protoplast fusion.

It is done during the process of somatic hybridisation.


***note: protoplast is the inner material of the cell without cell wall***



Question 11.

Why is it easier to culture meristems compared to permanent tissues?


Answer:

The meristems have the ability of division. They divide and differentiate into a new plant whereas the permanent tissues have lost the ability of division, so they cannot form a new plant.

Hence, it is easier to culture meristems compared to permanent tissues.



Question 12.

Why are proteins synthesised from Spirulina called single cell proteins?


Answer:

The single cell of Spirulina produces a large amount of protein within short span. The single cell is so rich in protein that it provides a good protein diet to the humans.

Hence, proteins synthesised from Spirulina are called single cell proteins.



Question 13.

A person who is allergic to pulses was advised to take a capsule of Spirulina daily. Give the reasons for the advise.


Answer:

Spirulina can be used as an alternative source of proteins for the humans. The single cell of Spirulina produces such large amount of proteins within short span and can be used by humans.

Pulses are rich in proteins and if the person is allergic to them then as a protein source, a capsule of Spirulina is advised regularly to such person.



Question 14.

What is aquaculture? Give example of an animal that can be multiplied by aquaculture.


Answer:

Aquaculture is defined as the culture or farming of all the aquatic plants and animals for economic use. Aquaculture is also known as aquafarming.

The animals that can be multiplied by aquaculture are fishes, lobsters, crabs, molluscs etc.



Question 15.

What are the duties of a veterinary doctor in management of a poultry farm?


Answer:

Duties of veterinary doctor in management of a poultry farm are:

i. Observing the behaviour of the animals.


ii. Giving basic check up at regular intervals.


iii. Ensuring proper feeding and water.


iv. Seeing the farm condition and keeping the environment healthy.


v. Giving vaccinations.


vi. Doing necessary analysis and checking the meat and the eggs.


These are the basic things that a veterinary doctor should see. Maintaining of healthy environment and keeping the animals diseased free, ensuring that they get proper food and water etc, are very important for a poultry farm to function properly. If the flocks are healthy, the yield will be good too.



Question 16.

Would it be wrong to call plants obtained through micro-propagation as ‘clones’? Comment.


Answer:

The plants produced by micro-propagation are genetically similar to the original parent from which they were grown.

A clone is a living organism produced asexually from a single parent and is genetically identical to it.


Hence, it will not be wrong to call plants obtained through micro-propagation as clones because the plant will be genetically identical to its parent.



Question 17.

How is a somatic hybrid different from a hybrid?


Answer:




Question 18.

What is emasculation? Why and when is it done?


Answer:

Emasculation is the process of removal of male reproductive part (stamens) from the flower, usually a bisexual flower.

Emasculation is done so that the flower becomes completely a female flower and there is no chance of self pollination or pollination by undesirable pollen. Emasculation is an important technique in hybridisation. It is done before the flowers attain maturity.



Question 19.

Discuss the two main limitations of plant hybridization programme.


Answer:

Two main limitations of plant hybridization programme are:

i. Availability of desirable traits: The plant hybridization is mostly dependent on the availability of desirable traits which is to be introduced in the next generation. Hence, availability of desirable traits in existing varieties and wild variety is a limitation.


ii. Linking of desirable trait to undesirable gene: Many a times a desirable trait is linked to the undesirable trait of the plant. The extraction of desirable traits from the undesirable ones creates a limitation to this programme too.



Question 20.

Interspecific crosses are rare in nature and intergeneric crosses almost unknown. Why?


Answer:

In inter-specific crossing the mating between the male and female of two different related species takes place. The progeny formed from such cross is generally infertile. Hence, inter-specific cross are rare in nature.

In inter-generic crossing, the crossing or mating is done between male and female of two different genus. It is completely impossible because different genus have different characters and the breeding cannot be done between two different genus.


For example: A cat cannot mate with a horse. The gametes of genus have different specificity and hence cannot be fused.


So, the inter-generic crosses are almost unknown in nature.



Question 21.

Differentiate between pisciculture and aquaculture.


Answer:




Question 22.

Give two important contributions of Dr. M. S. Swaminathan.


Answer:

Two important contributions of Dr. M. S. Swaminathan are:

i. Dr. M. S. Swaminathan is known as the ‘Father of Green Revolution’ in India. He developed high yielding varieties of wheat in India.


ii. He is an advocate of moving India to sustainable development.



Question 23.

The term ‘desirable trait’ can mean different things for different plants. Justify the statement with suitable examples.


Answer:

A character that is desirable and advantageous for one plant can be undesirable or a disadvantage for another plant.

For example: If the character of height is taken into consideration, tallness can be desirable for one plant whereas undesirable for another plant. Same is the case with the dwarfness.


Like for the cereal plants, dwarfness is a desirable trait not tallness. Similarly for the fodder and woody plants tallness is a desirable trait not dwarfness.




Short Answer Type
Question 1.

You are planning to set up a Dairy Farm. Describe the various aspects you would consider before you start the venture.


Answer:

Various aspects to be considered before setting the dairy farm are as follows:

1. Proper cattle management: It is necessary to have proper cattle management. All the necessary environment conditions are taking into consideration such as the availability of light and air. Proper drainage system with proper sanitation.


2. Food habit of cattle: The adequate availability of food is an important aspect while setting the dairy farm. The time and amount of food given to the cattle is taken into consideration.


3. Health Management: It is important to have arrangement of health care so as to look after the cattle and also to do the treatment of sick animals.


4. Marketing: The last step is the marketing of the products. The milk and other dairy products are marketed to different retailers or directly to the customers.



Question 2.

It is said, that diseases are spreading faster due to globalisation and increased movement of people. Justify the statement taking the example of H5N1 virus.


Answer:

• Globalization means coming of countries together as one big economy and making the international trade easier.


• Movement from one place to another is an important cause of globalisation.


• H5N1 virus is the avian influenza virus responsible for the bird flu.


• The bird flu is transmissible from organism to organism.


• The meat and egg especially have the virus particles. When the trading of eggs and the animals is done, the virus from the one place reaches another place. This is mainly due to the movement of people.


• Bird flu first started in West Bengal in 2008 and from there it was spread to the other states.


• The diseased animals when come in contact with the healthy ones, the virus particles are transferred to the healthy one making it diseased too.


• The contact of diseased animal with healthy animals was mainly due to the trading of animal and its product to the different places.


• The virus even have the ability to move from human to human, hence, is transferred to healthy individuals at a very fast pace.


Hence, diseases are spreading faster due to globalisation and increased movement of people.



Question 3.

Explain the concept of the Blue Revolution.


Answer:

Concept of blue revolution is given below:

• As the name suggest, the blue revolution is related to the aquatic plants and animals.


• In blue revolution there was a wide increase in the practice of aquaculture, in order to increase the production.


• Aquaculture refers to the farming of all forms of aquatic plants and animals be it marine or freshwater.


• The blue revolution resulted in the major increase in the aquatic organisms and their products.


• Many fresh water and marine organisms are cultivated as productive and nutritious food for human consumptions.


• This was not only economically important but also ecologically.



Question 4.

A farmer was facing the problem of low yield from his farm. He was advised to keep a beehive in the vicinity. Why? How would the beehive help in enhancing yield?


Answer:

• A beehive would have a large number of honey bees. Honey bee is the major pollinator of many plants.


• This would help in increasing the rate of the pollination.


• When beehive will be in vicinity of the farm, the pollination of the crops will takes place at a good rate.


• Good pollination results in the increase in the seed production, ultimately increasing the crop of plants.


• More crop means, more yield.


Hence, a farmer facing the problem of low yield from his farm was advised to keep a beehive in the close vicinity.



Question 5.

Life style diseases are increasing alarmingly in India. We are also dealing with large scale malnutrition in the population. Is there any method by which we can address both of these problems together?


Answer:

To address both the problems together, biofortification can be used.

• Biofortification is a technique of breeding crops with higher levels of nutrients example vitamin, minerals, proteins, fats etc.


• It is a major technique to improve the food quality.


• Consumption of food with higher healthy nutrient level is a means to improve public health.


• Many varieties of food such as maize hybrid with higher amino acid level, Atlas 66, a wheat variety having high protein content were produced.


Hence, biofortification can be used to decrease life style diseases as well as to deal with malnutrition in the population.



Question 6.

How can we improve the success rate of fertilisation during artificial insemination in animal husbandry programmes?


Answer:

Multiple Ovulation Embryo Transfer Technology (MOET) is used to improve the success rate of fertilization during artificial insemination in animal husbandry.

• In the method the cow is administered with certain hormone with FSH like activity.


• This hormone leads to the production of 6-8 eggs per cycle instead of one.


• The animal is then mated with an elite bull or is artificially inseminated.


• The fertilized egg at 8-32 cells stages is then recovered non-surgically and transferred to the surrogate mothers.


This technique ensures the increased production of herd in a short time.



Question 7.

What is meant by germplasm collection? What are its benefits?


Answer:

Germplasm collection in simple terms means the collection of genes.

In germplasm collection the entire collection of plants or seeds having all the diverse alleles for all genes in a given crop is done.


Benefits of germplasm collection:


• It is important to maintain biological diversity. Different varieties of genes are collected under the germplasm collection, thus, creating and maintaining biodiversity.


• The collection can be used in the future too. The genes are collected and stored and hence then can be used for the future need.


• It is important for food security too because the genes can be used for the production of desirable plant with good yield.



Question 8.

Name the improved characteristics of wheat that helped India to achieve green revolution.


Answer:

The improved characteristics of wheat that helped India to achieve green revolution are:

• Semi dwarf: The height of the improved plant was neither too short not too long, hence being semi dwarf.


• High yield: The yield of the improved wheat was very high as compared to the previous times.


• Disease resistance: Various varieties of the wheat were developed that do not allowed the disease to grow.


• Early maturity: Early maturity of the plant was necessary for high production.


Some examples of improved wheat varieties are Sonalika and Kalyan Sona etc.



Question 9.

Suggest some of the features of plants that will prevent insect and pest infestation.


Answer:

The features of plants that will prevent insect and pest infestation are:

Morphological features: Various plants have certain hair like structure in the stem and other parts of the plants, these features prevent insect pests.


Biochemical features: Certain biochemical products provide resistance to the plants from the insects and pests. Example: High aspartic acid, low nitrogen and sugar content in maize leads to resistance to maize stem borers. Release of certain toxic chemicals kills the insects and pests too.


Other features: Certain other features like nectar less variety and solid stem also do not attracts the insects and pests.



Question 10.

It is easier to culture plant cells in vitro as compared to animal cells. Why? +


Answer:

Plant cells have the ability of dedifferentiation. Dedifferentiation is the ability of the cells to lose as well as reverse the ability of differentiation. Plant cells undergo the process of dedifferentiation and became meristematic again.

Animal cells do not have any such property of dedifferentiation and hence, they do not have the property of division.


Hence, it is easier to culture plant cells in vitro as compared to animal cells.



Question 11.

The culture medium (nutrient medium) can be referred to as a ‘highly enriched laboratory soil. Justify the statement.


Answer:

A culture medium is defined as an artificially prepared growth medium. This medium has various nutrients, chemicals, growth regulators, food supplements that are needed for the proper growth and nourishment of the growing cell/organism.

Soil is a naturally occurring medium that has all the minerals, nutrients, decomposers, water and all the things required for the growth of organisms.


Hence, culture medium has almost the same function as soil and can be referred to as highly enriched laboratory soil.



Question 12.

Is there any relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments?


Answer:

Dedifferentiation is the very important feature of plant cells. Dedifferentiation is defined as the ability of the plants cells to reverse the process of differentiation.

The differentiated cells can lose differentiation property and become meristematic again by dedifferentiation. In this way the cells can divide again and can carry specific desirable functions.


This property of plant cells is very important in plant tissue culture, as any kind of tissue can be produced from differentiated cells.


Hence, there is a relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments.



Question 13.

“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:

The above statement is scientifically possible too.

Explanation:


• Tissue culture is the method through which we can produce thousands of plants of same type by a single cell.


• In this, an explants or any part of the plant is selected and is grown in test tube.


• The growth takes place under sterile conditions in special nutrient medium which contains carbon source, inorganic salts, amino acids, vitamins and other growth regulators.


• A whole plant can be generated from a single plant cell or an explant. This property is known as totipotency.


• Through totipotency a large number of plant can be produced which are genetically identical to the original plant from which they have been produced. Hence, they are known as somaclones and the method is known as micro-propagation.



Question 14.

What is the difference between a breed and a species? Give an example for each category.


Answer:

The difference between the breed and species is given in the table below:



Question 15.

Plants raised through tissue cultures are clones of the ‘parent’ plant. Discuss the utility of these plants.


Answer:

• Tissue culture is the method through which we can produce thousands of plants of same type by a single cell.


• In this, an explants or any part of the plant is selected and is grown in test tube.


• The growth takes place under sterile conditions in special nutrient medium which contains carbon source, inorganic salts, amino acids, vitamins and other growth regulators.


• A whole plant can be generated from a single plant cell or an explant. This property is known as totipotency.


• Through totipotency a large number of plant can be produced which are genetically identical to the original plant from which they have been produced. Hence, they are called clones.


Utility: The plants that are produced by tissue culture are used to produce thousand and more exact copies of an economically important plant. The tissue culture also helps in the recovery of the healthy plant from a diseased plant. Because even if the plant is affected with the virus, the meristems are free from it. Hence, the healthy meristems are removed from the plant and grown in vitro conditions to obtain virus free or healthy plants.



Question 16.

Discuss the importance of testing of new plant varieties in a geographically vast country like India.


Answer:

The importance of testing of new plant varieties in a geographically vast country like India are:

• The new plant varieties are grown in research fields in order to check the quality and quantity of the product.


• The testing is done to ensure whether the variety is disease free or not.


• Another reason for this testing is to ensure the high and nutritious yield of the plant.


• Another aspect is to the check the time taken for the growth of the plant.


• After all this evaluation is made, then the high yielding, diseased resistant and high quality varieties are grown for economic use.



Question 17.

Define the term ‘stress’ for plants. Discuss briefly the two types of stress encountered by plants.


Answer:

STRESS- Any negative impact on the plant that is caused due to any factor whether biotic or abiotic is known as stress. The stress affects the growth and development of the plant.


The two types of stress encountered by plants are:


1. Water stress: Water stress can be due to both: increased and decreased quantity of the water. If the water is less than the required amount it causes drought which dries up the plant and if the water is more than the required quantity then flood occurs, which too stresses the plant.


2. Salt stress: This is caused due to increase in the amount of salts in the soil solution. The plants take up large amount of the soil from the surrounding and it causes death of the cells.



Question 18.

Discuss natural selection and artificial selection. What are the implications of the latter on the process of evolution?


Answer:

Natural selection- Natural selection is the rule of the nature and it occurs naturally. The organism that is best suited to the environment and changes and adapts with time is naturally selected by nature.


Artificial selection- It is an artificial way of selecting of organisms and characters by the humans themselves. In artificial selection only those characters are selected that are beneficial to the human economy.


Artificial selection creates a change in the evolution process because in artificial selection new varieties are produced and in this way a new variety that is different from its parent occur in nature.



Question 19.

Discuss briefly how pure lines are created in animal husbandry.


Answer:

Pureline is a breed or strain of plants and animals that have homozygous alleles and have similar characters for various generations.

In animal husbandry, the purelines are created by repeated inbreeding or by the mating of male and female animal of the same breed for 4-5 generations.


Inbreeding increases homozygosity which in turn creates pure lines.


Hence, in animal husbandry pure lines are created by continued inbreeding.



Question 20.

What are the physical barriers of a cell in the protoplast fusion experiment? How are the barriers overcome?


Answer:

The most important and the only physical barrier of a cell in the protoplast fusion experiment is the cell wall.

This physical barrier is overcome by its breakdown. The breakdown of the cell wall is done by digesting the cell wall. The digestion of the cell wall is done by certain enzymes known as cell wall digesting enzymes. Certain cell wall digesting enzymes are cellulose, hemicellulase, pectinase etc.


After the digestion of the cell wall the protoplast becomes naked and now the fusion of two naked protoplasts takes place to form a hybrid.



Question 21.

Give few examples of biofortified crops. What benefits do they offer to the society?


Answer:

Example of biofortified crops are:

• Maize hybrid (It has twice the amount of amino acids, lysine and tryptophan.)


• Atlas 66, a wheat hybrid (It has high protein content.)


• Iron fortified rice (It has iron over five times more than the normal rice) etc


Benefits of biofotified crops:


1. These have high nutrient quantity.


2. It can be used to controlled malnutrition and other lifestyle disease.


3. These crops contain nutrients over five times more than present in the normal crops. Hence, they are nutritionally good.




Long Answer Type
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 various steps undertaken while releasing a new variety are as follows:

1. Collection of variability: It is a root of the plant breeding programme. The collection of all the available variety of genes and characters is done among all the wild variety present of the specific plant.


2. Evaluation and selection of parents: The above step ensures the collection of germplasm. After the collection another main task is to select the parents that have desirable traits and characters.


3. Cross hybridisation among the selected parents: It is an important time consuming task. The two parents with desirable traits are crossed such that both the desirable trait now occurs in one plant.


For example: a plant with disease resistant trait is crossed with high yielding plant, now the offspring has both the traits.


4. Selection and testing of superior recombinants: A very keen observation is done among the hybrids so as to select the superior hybrids that have the desirable characters of both the parents.


5. Testing, release and commercialisation of the new cultivars: After the selection of superior hybrids, they are grown in research fields so as to evaluate and test the quality and quantity of the product. Only that hybrid whose product is qualitatively and quantitatively good is released to grow economically.



Question 2.

(a) The shift from grain to meat diets creates more demands for cereals. Why?

(b) A 250 kg cow produces 200 g of protein per day but 250 g of Methylophillusmethylotrophus can produce 25 tonnes of protein Name this emerging area of research. Explain its benefits.


Answer:

(a) The shift from grains to meat diets create more demands for cereals because the humans consume meat which is obtained from animals such as goat, chicken, cow etc. These all animals are herbivores and they consume cereals and grasses for their nourishment. Also it takes 3-10kg of grain to produce 1kg of meat by animal farming.


(b) The name of this emerging area of research is Single Cell Protein. Single cell protein is used as the alternate source of proteins for animal and human nutrition. Single cell proteins are very advantageous as the microbes are grown in very large amount and they produce a large amount of proteins within short span of time. This protein can be consumed by animals and humans as the alternative source.


Hence, single cell protein is less time consuming, less product using and high yielding method. Also it helps in reducing environmental pollution because there is no misuse of products.



Question 3.

What are the advantages of tissue culture methods over conventional method of plant breeding in crop improvement programmes?


Answer:

The advantages of tissue culture methods over conventional method of plant breeding in crop improvement programmes are as follows:

1. Conventional breeding techniques failed to keep pace with the growing demands of the current time.


2. Tissue culture on the other hand can produce thousand of exact plant together in a very short time from a single cell/explant.


3. In this, an explants or any part of the plant is selected and is grown in test tube.


4. The growth takes place under sterile conditions in special nutrient medium which contains carbon source, inorganic salts, amino acids, vitamins and other growth regulators.


5. A whole plant can be generated from a single plant cell or an explant. This property is known as totipotency.


6. Through totipotency a large number of plant can be produced which are genetically identical to the original plant from which they have been produced. Hence, they are called clones.


7. The plants that are produced by tissue culture are used to produce thousand and more exact copies of an economically important plant.


8. The tissue culture also helps in the recovery of the healthy plant from a diseased plant. Because even if the plant is affected with the virus, the meristems are free from it. Hence, the healthy meristems are removed from the plant and grown in vitro conditions to obtain virus free or healthy plants.



Question 4.

‘Modern methods of breeding animals and plants can alleviate the global food shortage’. Comment on the statement and give suitable examples.


Answer:

Modern methods of breeding animals and plants can alleviate the global food shortage’. This sentence can be proved by the following examples:

1. MOET:


Multiple Ovulation Embryo Transfer Technology (MOET) is used to improve the success rate of fertilization during artificial insemination in animal husbandry.


• In the method the cow is administered with certain hormone with FSH like activity.


• This hormone leads to the production of 6-8 eggs per cycle instead of one.


• The animal is then mated with an elite bull or is artificially inseminated.


• The fertilized egg at 8-32 cells stages is then recovered non-surgically and transferred to the surrogate mothers.


• This technique ensures the increased production of herd in a short time.


2. SINGLE CELL PROTEIN:


• Single cell protein is used as the alternate source of proteins for animal and human nutrition.


• Single cell proteins are very advantageous as the microbes are grown in very large amount and they produce a large amount of proteins within short span of time.


• This protein can be consumed by animals and humans as the alternative source.


Hence, single cell protein is less time consuming, less product using and high yielding method. Also it helps in reducing environmental pollution because there is no misuse of products.


3. BIOFORTIFICATION:


• Biofortification is a technique of breeding crops with higher levels of nutrients example vitamin, minerals, proteins, fats etc.


• It is a major technique to improve the food quality.


• Consumption of food with higher healthy nutrient level is a means to improve public health.


• Many varieties of food such as maize hybrid with higher amino acid level, Atlas 66, a wheat variety having high protein content were produced.


• Hence, biofortification can be used to improve the nutrient content in food products.


4. TISSUE CULTURE:


• Tissue culture is the method through which we can produce thousands of plants of same type by a single cell.


• In this, an explants or any part of the plant is selected and is grown in test tube.


• The growth takes place under sterile conditions in special nutrient medium which contains carbon source, inorganic salts, amino acids, vitamins and other growth regulators.


• A whole plant can be generated from a single plant cell or an explant.


• The tissue culture also helps in the recovery of the healthy plant from a diseased plant. Because even if the plant is affected with the virus, the meristems are free from it. Hence, the healthy meristems are removed from the plant and grown in vitro conditions to obtain virus free or healthy plants.


All of the above listed methods are the modern breeding methods. They all are less time consuming and high yielding methods that to a large extent have decreased the food shortage.



Question 5.

Does apiculture offer multiple advantages to farmers? List its advantages if it is located near a place of commercial flower cultivation.


Answer:

Apiculture is the maintenance of hives of honeybees for the production of honey. It is also known as bee keeping.

Apiculture offers multiple advantages to the farmers.


1. It provides honey and wax and other honey products. The farmers dell these and get extra money.


2. The honey bees are the good pollinators.


3. A beehive would have a large number of honey bees. Honey bee is the major pollinator of many plants.


4. This would help in increasing the rate of the pollination.


5. When beehive will be in vicinity of the farm, the pollination of the crops will takes place at a good rate.


6. Good pollination results in the increase in the seed production, ultimately increasing the crop of plants.


7. More crop means, more yield.


Hence, apiculture offers multiple advantages to the farmer.



Question 6.

(a) Mutations are beneficial for plant breeding. Taking an example, justify the statement. (b) Discuss briefly the technology that made us self-sufficient in food production.


Answer:

(a) Mutation is a process by which the genetic sequence of the plant can be alter. Mutations can occur naturally and it is induced too. The mutations have helped in improving the quality of the crops. Artificially mutation is induced by gamma rays and then a plant with desirable trait is selected. Artificial mutation is known as mutation breeding.


Example: In mung bean, resistance to yellow mosaic virus and powdery mildew were induced by mutations.


(b) The technology that has made us self sufficient in the food production is plant breeding.


In order to release a variety certain steps are taken into consideration and then the best variety of plant with desirable traits is grown. The improvement found in the crops is the development of semi-dwarf variety, high yielding and disease resistant variety and early maturity variety.



Question 7.

Discuss how the property of plant cell totipotency has been utilised for plant propagation and improvement


Answer:

• Tissue culture is the method through which we can produce thousands of plants of same type by a single cell. This ability of development of whole plant from single cell is known as totipotency.


• In this, an explants or any part of the plant is selected and is grown in test tube.


• The growth takes place under sterile conditions in special nutrient medium which contains carbon source, inorganic salts, amino acids, vitamins and other growth regulators.


• A whole plant can be generated from a single plant cell or an explant.


• Totipotency helps in the production of thousands of plants that are genetically similar. This large scale production of plants is known as micro-propagation.


• The tissue culture also helps in the recovery of the healthy plant from a diseased plant. Because even if the plant is affected with the virus, the meristems are free from it. Hence, the healthy meristems are removed from the plant and grown in vitro conditions to obtain virus free or healthy plants.



Question 8.

What are three options to increase food production? Discuss each giving the salient features, merits and demerits.


Answer:

Three options to increase food productions are:

(a) Multiple Ovulation Embryo Transfer Technology is one way to increase food production. In this using certain hormone the production of egg is increased per cycle such that mating of one pair can give rise to many offspring together.


DEMERIT: The technology required is high level. It is costly method. The success rate is also low. Although the method give many offspring at a time but is time consuming.


(b) Tissue culture is another way that helps in the production of large number of plants within a very short span of time with just single cell. Apart from increase in yield, it also helps in the regeneration of diseased free plant.


DEMERIT: In tissue culture all the offsprings are genetically identical, hence there are chances of reduction of genetic diversity.


(c) Single cell protein is an alternative source of protein obtain from microbes. The cost of production of microbes is very less, the time taken to generate the protein is nil and the amount of protein generated is very large.


DEMERIT: Although the growth of microbes is a cheap process but their maintenance is a very costly process. Uses high technology in order to produce the medicines etc. Chances of it becoming toxic due to any infection in the microbes.