CBSE Class 12 Biology Strategies for Enhancement In Food Production Worksheet Set A

Important Questions for NCERT Class 12 Biology Strategies for Enhancement in Food Production

Question. Root of any plant breeding programme is :
(a) Mutation
(b) Genetic variability
(c) Hybridisation
(d) Selection

Answer : B

Question. The contribution of agriculture in indian GDP is approximately :
(a) 62%
(b) 90%
(c) 33%
(d) 5%

Answer : C

Question. Each of the plant obtained through tissue culture are genetically identical to the original plant from which they were grown are known as
(a) Genocopies
(b) Somaclonal variants
(c) Somaclones
(d) Phenocopies

Answer : C

Question. Sonalika is variety of :
(a) Wheat
(b) Rice
(c) Maize
(d) Pea

Answer : A

Question. "International center for wheat and maize"improvement" is situated at :
(a) Phillipins
(b) India
(c) Mexico
(d) Brazil

Answer : C

Question. Match the following
A. Vitamin A rich i Lablab
B. Vitamin C rich ii Spinach
C. Fe and Ca Rich iii Bitter gaurd
D. Protein Rich iv Carrot
      A  B  C  D
(a) iv  iii  ii  i
(b) iv  iii  i  ii
(c) iii  iv  ii  i
(d) iii  iv  i  ii

Answer : A

Question. Fusion between two naked protoplasts is known as
(a) Somatic hybridisation
(b) Germinal hybridisation
(c) Parasexual hybridisation
(d) Both 1 and 3

Answer : D 

Question. Parbhani Kranti, which has resistance to yellow mosaic virus is a variety of :
(a) Wheat
(b) Cow pea
(c) Bhindi
(d) Chilli

Answer : C

Question. Classical plant breeding involves
(a) Hybridisation of pure lines exclusively
(b) Hybridisation of pure lines followed by artificial selection
(c) Artificial selection exclusively
(d) Mutation breeding

Answer : B

Question. Which of the following is not an objective of plant breeding for improved nutritional quality
(a) Protein content and quality
(b) Oil content and quality
(c) Vitamin content
(d) Carbohydrate content

Answer : D

Question. Which of the following nutrient was enhanced in hybrid maize developed in the year 2000
(a) Lysine
(b) Tryptophane
(c) Threonine
(d) Both 1 and 2

Answer : D

Question. Which of the following is not a step of plant breeding
(a) Collection of variability
(b) Evalution and selection of parents
(c) Cross hybridisation within a pure line
(d) Selection and testing of superior recombinants

Answer : C

Question. Plants produced by tissue culture method are called:
(a) Explant
(b) Somaclones
(c) Micropropagation
(d) SCP (Single cell protein)

Answer : B

Question. India has maximum genetic diversity of :
(a) Wheat
(b) Rice
(c) Mango
(d) Apple

Answer : B

Question. In mung bean, resistance to yellow mosic virus and powdery mildew were induced by
(a) Conventional breeding
(b) Mutation breeding
(c) Germplasm collection
(d) Polyploidy breeding

Answer : B

Question. About disease resistant varieties of plant select out the incorrect match
(a) Wheat - Himgiri
(b) Brassica - Pusa swarnim
(c) Cauliflower - Pusa shubhra
(d) Cowpea - Pusa snowball K1

Answer : D

Question. Resistance to jassids in cotton and cereal leaf beetles in wheat is due to which of the following morphological / physiological / Biochemical characteristic
(a) Solid stem
(b) Nectorlessness
(c) High aspartic acid
(d) Hairy leaves

Answer : D

Question. Parbhani kranti variety of Ablemoschus esculentus was created for resistance against which of the following disease
(a) Yellow mosaic virus
(b) Curl blight black rot
(c) White rust
(d) Powdery mildew

Answer : A

Question. In India, how many varieties of rice are present ?
(a) 200000
(b) 50000
(c) 10000
(d) 1000

Answer : A

Question. Pomato is an example of :
(a) Somatic hybrid
(b) Somatic embryo
(c) Androgenic haploid
(d) SCP

Answer : A

Question. 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. A

Question. Inbreeding is carried out in animal husbandry because it 
(a) increases vigour
(b) improves the breed
(c) increases heterozygosity
(d) increases homozygosity
Answer. D

Question. Protoplast is 
(a) another name for protoplasm
(b) an animal cell
(c) a plant cell without a cell wall
(d) a plant cell.
Answer. C

Question. “Jaya” and “Ratna” developed for Green revolution in India are the varieties of
(a) maize
(b) rice
(c) wheat
(d) bajra
Answer. B

Question. 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. B

Question. Somaclones are obtained by
(a) plant breeding
(b) irradiation
(c) genetic engineering
(d) tissue culture
Answer. D

Question. Bull semen for the purpose of artificial insemination is stored in
(a) ice
(b) liquid oxygen
(c) liquid nitrogen
(d) liquid CO₂
Answer. C

Question. 33 percent of India’s Gross Domestic Product comes from 
(a) industry
(b) agriculture
(c) export
(d) small-scale cottage industries
Answer. B

Question. 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. C

Very Short Answer Questions

Question. Write the name of the following:
(a) The most common species of bees suitable for apiculture.
(b) An improved breed of chicken. 
Answer. (a) Apis indica/Apis mellifera/Apis dorsata
(b) Leghorn/Rhode island red/Minorca.

Question. Mention the strategy used to increase homozygosity in cattle for desired traits.
Answer. Inbreeding

Question. Write the importance of MOET.
Answer. MOET is used to increase the herd size in a short time. It also improves the chances of production of hybrids.

Question. Write an alternate source of protein for animal and human nutrition. 
Answer. Single cell protein/Spirulina

Question. Name the following:
(a) The semi-dwarf variety of wheat which is high-yielding and disease-resistant.
(b) Any one inter-specific hybrid mammal. 
Answer. (a) Kalyan Sona/Sonalika
(b) Mule/Hinny/Liger/Tigon

Question. Select two disease resistant crop varieties from the list of crop varieties given below:
Himgiri, Pusa Gaurav, Pusa Komal, Pusa A-4
Answer. Himgiri; Pusa Komal

Question. Why is the South Indian sugarcane preferred by agriculturalists? 
Answer. South Indian sugarcane has thicker stem and higher sugar content.

Question. Name any two diseases the ‘Himgiri’ variety of wheat is resistant to. 
Answer. Leaf and stripe rust; Hill bunt

Question. What is meant by ‘hidden hunger’? 
Answer. Consumption of food deficient in nutrients particularly, micronutrients, proteins and vitamins is called hidden hunger.

Question. State any one significance of interspecific hybridisation in plants. 
Answer. It is important for breeding disease-resistant plant varieties.

Question. Why are apical and axillary meristems used for tissue culture?
Answer. Because these are free from virus.

Short Answer Questions

Question. What kind of areas are suitable for practicing apiculture? Write the scientific name of the variety commonly reared for the purpose. 
Answer. Bee pastures of wild shrub, fruit orchards and cultivated crop are suitable for practicing apiculture.
The commonly reared variety for this purpose is Apis indica.

Question. Keeping beehives in crop fields has several advantages. List any two. [CBSE Sample Paper 2016]
Answer. (i) Pollination management
(ii) Versatile use of resources
(iii) Honey production at no cost

Question. (a) List two advantages of keeping beehives in a crop field during flowering season.
(b) Name one annual and one perennial crop species favourable to beeswax collection.
OR
Give the scientific name of the most common species of honey bee reared in India. Why is it advantageous to keep beehives in crop-fields during flowering periods? 
Answer. (a) The most common species of honey bee reared in India is Apis indica. Honeybees are good pollinators of almost all the plants. The flowers in turn offer floral rewards like nectar and pollen grains. So, when beehives are kept in crop-fields during the flowering season, honey collection increases and in turn the crop yield also increases.
(b) Annual crop: Sunflower/Brassica
Perennial crop: Apple/pear

Question. State the disadvantage of inbreeding among cattle. How it can be overcome? 
Answer. Continuous inbreeding reduces fertility and productivity. This is called inbreeding depression.
This can be overcome by mating with animal of different breeds or individuals of the same breed with unrelated superior animals.

Question. Describe the technology that has successfully increased the herd size of cattle in a short time
to meet the increasing demands of growing human population. 
Answer. Multiple ovulation embryo transfer technology (MOET) has successfully increased the herd size of cattle. The cow is administered with FSH to induce follicular maturation and super-ovulation to produce 6 to 8 eggs per cycle. It is then mated or artificially inseminated. The fertilised eggs are recovered non-surgically and transferred to surrogate mother where they develop into an improved variety.

Question. In MOET technology, two ‘mothers’ are needed to produce one calf. Justify. 
Answer. In MOET technology, one mother cow is administered hormones to induce follicular maturation and superovulation. These fertilised eggs are transferred to the second surrogate mothers for development.

Question. What is inbreeding depression? Why do the self-pollinated crops not show the ill effects of inbreeding depression?
Answer. The continuous inbreeding may lead to reduced fertility and productivity called inbreeding depression. Self-pollinated crop does not show the ill effects of inbreeding depression because the deleterious allele becomes homozygous and exhibits their lethal effect so it is eliminated by selection.

Question. “Artificial insemination helps overcome several problems of normal mating in cattle”. Do you agree? Support your answer with any three reasons. 
Answer. This statement is completely justified.
(i) It helps in selective breeding in animals.
(ii) Semen of a single bull can be used to impregnate several females.
(iii) Quality semen is available in preserved form all the time at all places.
(iv) Frozen semen can be exported or imported. It is the most reliable method.
(v) It does not spread contagious diseases.

Question. How can we improve the success rate of fertilisation during artificial insemination in animal husbandry programmes?
Answer. The technology called MOET or Multiple Ovulation Embryo Transfer is used to increase the success rate. 
- It is a programme for herd improvement in animals like cattle, sheep, rabbits, buffaloes, mares, etc.
- High milk-yielding breeds of female have been bred with high quality (lean meat with less lipid) meat-yielding bulls to increase herd size in lesser time.

Question. Explain the advantage of cross-breeding of the two species of sugarcane in India.
Answer. Saccharum barberi, grown in north India, had poor sugar content and yield, whereas Saccharum officinarum, grown in south India, had thicker stem and higher sugar content. The sugarcane species obtained after cross breeding these two species had thick stems, high sugar, high yield and ability to grow in north India.

Question. What is outbreeding? Mention any two ways it can be carried out. 
Answer. Outbreeding refers to the breeding of unrelated animals either of the same breed but not having common ancestors or of different breeds or even different species.
It can be carried out by:
(i) Outcrossing
(ii) Cross-breeding
(iii) Interspecific hybridisation

Question. Differentiate between outbreeding and outcrossing. 
Answer. Outbreeding is breeding of unrelated animals (having no ancestors for 4–6 generations) belonging to same breed or different breeds or different species.
Outcrossing is breeding within the animals of same breed having no common ancestors for 4–6 generation on either side of the pedigree.

Question. Name any two common Indian millet crops. State one characteristic of millets that has been improved as a result of hybrid breeding so as to produce high yielding millet crops.
Answer. Maize, jowar, bajra (Any two)
Resistant to water stress has been improved.

Question. Enumerate four objectives for improving the nutritional quality of different crops for the health benefits of the human population by the process of “Biofortification”. 
Answer. (i) Improving protein content and quality.
(ii) Improving oil content and quality.
(iii) Improving vitamin content and quality.
(iv) Improving micronutrient or mineral content.

Question. List the two steps that are essential for carrying out artificial hybridisation in crop plants and why. 
Answer. (a) Selection of parents: Only those plants should be selected which have desired traits.
(b) Crossing over: Pollen grains from selected male plant is collected and transferred to the female plant after which it is bagged.

Question. Scientists tried to develop a single plant exhibiting the characteristic of tomato and potato by using cells from tomato and potato plants respectively. Name the procedure and list the steps to achieve this.
Answer. The procedure followed by the scientists is somatic hybridisation.
It involves isolation of protoplast of tomato cell and potato cell having desirable character. These protoplasts fused to get hybrid protoplast which was further grown to form a new plant.

Question. By taking two examples explain how has biofortification helped in improving food quality.
Answer. Biofortification has improved protein content and quality, oil content and quality, vitamin content, micronutrients and mineral content. For example, Atlas 66 has been used as a donor for developing wheat varieties with improved protein content. Maize hybrids have been developed with increased amount of amino acids, lysin and tryptophan.

Question. How are biofortified maize and wheat considered nutritionally improved? 
Answer. Biofortified maize has twice the amount of amino acids, lysine and tryptophan, compared to existing hybrids and the wheat variety has increased protein content.

Question. Plant breeding technique has helped sugar industry in North India. Explain how.
Answer. 
- Saccharum barberi and Saccharum officinarum were crossed to obtain sugarcane varieties having desirable qualities.
- S. barberi was grown in north India and had poor sugar content and yield.
- S. officinarum did not grow in north India but had thicker stem and higher sugar content.
- The new sugarcane varieties formed by crossing the two varieties had the following qualities:
(a) high yield,
(b) thick stem,
(c) high sugar content,
(d) ability to grow in north India.

Question. Write the importance of bagging of unisexual flowers in crop improvement programme.
Answer. The emasculated flowers are covered with a bag of butter paper to prevent contamination of stigma with unwanted pollen. This process is called bagging. When this stigma attains receptivity, mature pollen grains are dusted on the stigma and the flowers are rebagged to allow the fruits to develop.

Question. Identify ‘A’, ‘B’, ‘C’ and ‘D’ in the given table.

Answer.

Question. (a) Why are the plants raised through micropropagation termed as somaclones?
(b) Mention two advantages of this technique. 
Answer. (a) Plants raised through micropropagation are genetically identical, hence the name somaclones.
(b) (i) Large number of plants are produced in short duration.
(ii) Virus-free plants are produced.

Question. (i) Mention the property that enables the explants to regenerate into a new plant.
(ii) A banana herb is virus-infected. Describe the method that will help in obtaining healthy banana plants from this diseased plant.
OR
How is it possible to recover healthy banana plants from a diseased but desirable quality banana plant? Explain.
Answer. (i) Totipotency is the ability of a cell to grow or generate the whole plant.
(ii) Healthy banana plants can be obtained from diseased plants by meristem culture. Although the plant is virus infected, the apical and axillary meristem is free of virus. The meristem is removed from the plant and grown in vitro by micropropagation. The plants produced are virus-free.

Question. How can healthy potato plants be obtained from a desired potato variety which is viral infected? Explain.
Answer. Even though a plant is infected by a virus, the meristem (apical or axillary) is free of virus. So the meristem can be removed and grown in vitro, under sterile conditions and special nutrient/ culture medium.

Question. How does culturing Spirulina solve the food problems of the growing human population?
OR
“Large scale cultivation of Spirulina is highly advantageous for human population.” Explain giving two reasons.
Answer. Microbes are being grown on an industrial scale as source of good protein. Microbes like Spirulina can be grown easily on materials like waste water from potato processing plants (containing starch), straw, molasses, animal manure and even sewage, to produce large quantities and can serve as food rich in protein, minerals, fats carbohydrate and vitamins. Incidentally such utilisation also reduces environmental pollution and hence is environment friendly.

Question. Identify two ways in which Spirulina is helpful to mankind.
Answer. Spirulina is a source of food rich in protein, minerals, fats, carbohydrates and vitamins. It can grow on waste water from potato processing plants, straw, molasses, animal manure and even sewage, so it also reduces water pollution.

Question. Demand for mushroom as food has led to its culturing on a large scale. Similarly, it is perceived that microbes too would become acceptable as food. Identify a microbe which can be cultured as a food source and give the applicability of its culture in the given context.
OR
To reduce the percentage of population suffering from hunger and malnutrition, microbes are grown on a large scale to act as food supplements. Mention any two microbes used as food supplement and suggest their role. 
Answer. The two microbes used as food supplements are:
(i) Spirulina: Produces large quantities of food rich in protein, minerals, fats, carbohydrates and vitamins.
(ii) Methylophilus methylotrophus: 250 gm of this microorganism produces 25 tonnes of protein per day.

Question. Lifestyle 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 these problems? 
Answer. The answer to address both these problems is biofortification. This looks at improving food quality with respect to protein, oil, vitamin, micro-nutrient and mineral content. The oils need to be rich in omega-3 fatty acids which are good for heart. Similarly, proteins should have more of lysine and tryptophan (essential amino acids). Many varieties of maize, carrots and spinach have been released with increased content of vitamin A, vitamin C, iron and calcium which fulfill the above criteria.

Question. “Growing Spirulina on a large scale is beneficial both environmentally and nutritionally for
humans.” Justify. 
Answer. Spirulina can be grown easily on materials like waste water from potato processing plants, straw, molasses, animal manure, sewage. This way it reduces environmental pollution and hence is environmentally beneficial. It serves as food rich in protein, carbohydrate, fats, vitamins and minerals. Thus, it is nutritionally beneficial too.

Question. How are somaclones cultured from explants in in vitro conditions? Why are somaclones so called? 
Answer. A part of the plant called explant is taken for tissue culture. The explant is grown in aseptic condition in synthetic/cultural media which is rich in inorganic nutrients, vitamins, amino acids and growth regulators like cytokinin and auxin. The method of growing or producing thousands of plants through tissue culture is called micropropagation.
The plants produced from tissue culture are genetically identical to the original plant from which they are grown, so they are called somaclones.

Question. Suggest two features of plants that will prevent insect and pest infestation. 
Answer. (i) Increasing hair growth on aerial parts of plants.
(ii) Rendering the flowers nectar less.
(iii) Enabling plants to secrete insect killing chemicals (toxins).

Question. Fill in the blanks.

Answer. I— Protoplasts; II— Somatic hybridisation; III— Pomato; IV— Somatic hybrid

Question. Give two examples of biofortified crops. What benefits do they offer to the society?
Answer. Maize, wheat, rice, bathua, spinach, pulses have biofortified varieties. Maize hybrids have twice the amount of amino acids, fortified wheat variety has high protein content, fortified rice has high quantity of iron. Consumption of such biofortified foods will enrich the nutritive value of our common foods and will vastly improve public health. It may even help overcome several nutrient deficiency disorders latent in our country.

Question. Name the improved characteristics of wheat that helped India achieve green revolution.
Answer. (i) Semi-dwarf nature
(ii) Quick yielding feature
(iii) High yielding feature
(iv) Disease resistant feature

Question. Suryakant had banana plantation in his field. Quality of the fruit was excellent but the yield suffered due to infection of the plants by a virus. Suggest a fast and efficient method to get healthy and a large number of plants in the next generation without compromising on the existing quality. Justify the selection of your method. 
Answer. He can grow thousands of plants through tissue culture of meristem by micro-propagation. He can remove the meristem and grow it in vitro using tissue culture technique. Although the plant is infected with a virus, the meristem (apical and axillary) is free of viruses.

ENHANCEMENT IN FOOD PRODUCTION

1 Define inbreeding depression. How the harmful effects of inbreeding depression can be overcome?

2 a) What is heterosis? b) Explain biofortification and mutation breeding methods of plant breeding to improve quality and quantity of yield.

3 a) Define totipotency. How is this ability useful to the tissue culture method?

b) What are somaclonal variations? Do they have any significance in tissue culture?

4 What is out crossing?

5 List any two economically important products for humans obtained from Apis indica.

6 How are the two following varieties of sugarcane different from each other? i) Saccharum barberi ii) Saccharum officinarum

7 Mention the strategy used to increase homozygosity in cattle for desired traits.

8 MOET program has helped in increasing the herd size of the desired variety of cattle. List the steps involved in conducting the program.

9 How are somaclones cultured from explants in in-vitro conditions? Why are somaclones so called?

10 Suggest and describe a technique through which a virus-free healthy plant can be obtained from a diseased sugarcane plant.

11 a)What is micropropagation?

 b) Name the technique by which healthy plants can be recovered from the diseased plants.

12 Explain the efforts which must be put to improve health, hygiene and milk yield of cattle in a dairy farm.

13 (a) State the objective of animal breeding. 

(b) List the importance and limitations of inbreeding. How can we overcome the limitations? 

(c) Give an example of a new breed each of cattle and poultry.