Please refer to Strategies for Enhancement in Food Production Class 12 Biology Important Questions with solutions provided below. These questions and answers have been provided for Class 12 Biology based on the latest syllabus and examination guidelines issued by CBSE, NCERT, and KVS. Students should learn these problem solutions as it will help them to gain more marks in examinations. We have provided Important Questions for Class 12 Biology for all chapters in your book. These Board exam questions have been designed by expert teachers of Standard 12.
Class 12 Biology Important Questions Strategies for Enhancement in Food Production
Very Short Answer Questions
Question. Which part of the plant is best suited for making virus-free plants and why?
Ans. The terminal bud having apical meristem are the best suited parts of plant for making virus-free plant because they are not infected by virus.
Question. State any one significance of interspecific hybridisation in plants.
Ans. It is important for breeding disease-resistant plant varieties.
Question. Name the technology which in addition to tissue culture techniques play a pivotal role in enhancing food production.
Ans. Somatic hybridisation, Multiple Ovulation Embryo Transfer Technology
Question. Write the names of two semi-dwarf and high yielding rice varieties developed in India after 1966.
Ans. Jaya, Ratna.
Question. Why is mutation breeding necessary for producing disease resistance varieties?
Ans. Because there is limited availability of disease resistance genes in the crop plants and their wild relatives.
Question. Explain what is meant by biofortification.
Ans. Biofortification is a crop breeding programme that is aimed for developing crop with high levels of vitamins, minerals, proteins and fats to improve public health.
Short Answer Questions
Question. State the disadvantage of inbreeding among cattle. How it can be overcome?
Ans. 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. Identify two ways in which Spirulina is helpful to mankind.
Ans. 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. Find out what the various components of the medium used for propagation of an explant in vitro are.
Ans. The major components of the medium for in vitro propagation are:
(i) Water (ii) Agar agar (iii) Sucrose
(iv) Inorganic salts (v) Vitamins (vi) Amino acids
(vii) Growth hormones like auxin, cytokinins.
Question. “Growing Spirulina on a large scale is beneficial both environmentally and nutritionally for humans.” Justify.
Ans. 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. Identify A, B, C and D in the table given below.
|Crop||Variety||Resistance to disease|
|Wheat||A||Leaf and stripe rust|
Ans. A : Himgiri B : Cauliflower
C : Bacterial blight D : White rust
Question. How are somaclones cultured from explants in in vitro conditions? Why are somaclones so called?
Ans. 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. How has mutation breeding helped in improving the production of mung bean crop?
Ans. Mutation breeding has helped in the production of disease resistant varieties of mung bean crops against yellow mosaic virus and powdery mildew.
Question. Suggest two features of plants that will prevent insect and pest infestation.
Ans. (i) Increasing hair growth on aerial parts of plants.
(ii) Rendering th eflowers necta r less.
(iii) Enabling plants to secrete insect killing chemicals (toxins).
Question. Explain in brief the role of animal husbandry in human welfare.
Ans. Animal husbandry is the practice of taking care and breeding domestic animals by applying scientific principles. It includes feeding, breeding and raising animal livestock whose primary purpose is to provide meat and milk. Milk is considered as an important article of regular diet.
The animal protein is obtained from beef, cattle, sheep and meat of goats. Eggs and poultry meat also serve as sources of animal protein. Thus, animal husbandry plays an important role in human welfare by providing us milk, eggs, meat, wool, silk, honey, wax and many other products. Also, rearing of animals provide useful employment to many.
Question. Fill in the blanks.
Ans. I— Protoplasts; II— Somatic hybridisation; III— Pomato; IV— Somatic hybrid
Question. Name any five hybrid varieties of crop plants which have been developed in India.
Ans. (i) Cauliflower varieties — Pusa Shubhra and Pusa Snowball K-1
(ii) Brassica varieties — Pusa Swarnim (Karan rai)
(iii) Wheat varieties — Himgiri
(iv) Rice varieties — Jaya and Ratna
(v) Chilli varieties — Pusa Sadabahar.
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.
Ans. 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.
Long Answer Questions
Question. According to Global Hunger Index, 2014, two billion people suffer from hidden hunger.
Apply your knowledge of plant breeding techniques to suggest a programme to improve public health. Specify four objectives of the programme. Also, mention one example of such a
Ans. Biofortification can improve public health. It involves breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fats.
Breeding for improved nutritional quality is improving:
(i) Protein content and quality;
(ii) Oil conten atnd quality;
(iii) Vitamin content; and
(iv) Micronutrient and mineral content.
In the year 2000, maize hybrids that had twice the amount of the amino acids, lysine and tryptophan, compared to existing maize hybrids were developed. Another example is the wheat variety, Atlas 66, having a high protein content which has been used as a donor for improving cultivated wheat.
Question. (a) State the objective of animal breeding.
(b) List the importance and limitations of inbreeding. How can the limitations be overcome?
(c) Give an example of a new breed each of cattle and poultry.
Ans. (a) Objective of animal breeding is to increase the yield of animal and improve the desirable qualities of the produce.
(i) Increases homozygosity
(ii) Evolves pure line
(iii) Expose harmful recessive genes
(iv) Help in accumulation of superior genes
(v) Eliminate less desirable genes.
Inbreeding reduces fertility and productivity (inbreeding depression).
The limitations can be overcome by outbreeding or out-crossing or interspecific hybridisation.
Selected animals may be bred with unrelated superior animals of the same breed.
(c) Hisardale is a new breed developed by crossing Bikaneri ewes and Mirano rams (sheep) and Leghorn is the new breed of chicken and Jersey is improved breed of cattle..
Question. IARI has released several varieties of crop plants that are biofortified. Give three examples of such crops and their biofortifications.
Ans. (i) Bittergourd enriched with vitamin C.
(ii) Carrots enriched with vitamin A.
(iii) Spinach enriched with iron and calcium.
Question. (i) Name the tropical sugarcane variety grown in South India. How has it helped in improving the sugar cane quality grown in North India?
(ii) Identify ‘a’, ‘b’ and ‘c’ in the following table:
Pusa Sem 2
Pusa Sem 3
Shoot and Fruit borer
Ans. (i) Saccharum officinarum is grown in South India. It was crossed with North Indian variety (Saccharum barberi) to combine the desirable qualities of high yield, thick stems high sugar and ability to grow in North India.
(ii) (a) Aphids
(b) Jassids/aphids/fruit borer
(c) Okra B( hindi).
Question. (a) Name the technology that has helped the scientists to propagate on large scale the desired crops in short duration. List the steps carried out to propagate the crops by the said technique.
(b) How are somatic hybrids obtained?
Ans. (a) The technology that has helped the scientists to propagate on large scale the desired crops is tissue culture or micropropagation.
The steps to propagate crops are:
(i) Obtaining an explant from a plant.
(ii) Growing the explant in a test tube under sterile conditions.
(iii) A special nutrient or culture medium is provided for growth.
(b) Isolated single cells are isolated from plants. Their cell walls are digested to obtain protoplasts.
Isolated protoplasts from two different plant varieties are fused to get hybrid protoplasts.
(v) Testing, release and commercialisation of new cultivars. Newly selected lines are evaluated for yield and other agronomic traits of quality or disease resistance in research fields followed by testing the material in farmers fields for three seasons in different agroclimatic zones.
Question. Differentiate between an inbred line and a hybrid variety of crop. Explain the steps involved in the production of the hybrid variety.
|Inbred line||Hybrid variety|
|The continuous inbreeding in a cross-pollinated|
crop develops a homozygous line called inbred
|A hybrid variety is produced by crossing two|
different species where progeny obtained is used
for raising the next seasonal crop.
Steps involved in hybrid variety production: