NEET Biology Strategies For Enhancement Important Questions Set 01

These Class 12 NEET Biology important questions on Strategies For Enhancement give 45 questions with step-by-step answers, arranged as very short, short and long answer types, as asked in school and board examinations. They help NEET aspirants revise the definitions, structures, differences and key terms of the chapter.

Very Short Answer Type Questions

Question 1. What is the germplasm collection?
Answer: The entire collection of plants/seeds having all the diverse alleles for all genes in a given crop is called germplasm collection.

Question 2. Which process is crucial to the success of the breeding objective?
Answer: The selection of superior hybrid is crucial to the success of the breeding objective.

Question 3. What percentage of India's GDP is supported by agriculture?
Answer: 33 percent of India's GDP is supported by agriculture.

Question 4. Which varieties were introduced all over the wheat growing belt in India in 1963?
Answer: Sonalika and Kalyan Sona.

Question 5. Give the name of two diseases caused by fungi.
Answer: (i) Brown rust of wheat.
(ii) Late blight of potato.

Question 6. What is the conventional method of breeding for disease resistance?
Answer: Hybridisation and selection.

Question 7. Give the name of cowpea crop variety which is resistant to bacterial blight.
Answer: Pusa Komal.

Question 8. Which breeding method was used in mung bean to develope resistance to yellow mosaic virus?
Answer: Mutation breeding.

Question 9. Give the name of wheat variety having high protein content.
Answer: Atlas-66.

Question 10. What is totipotency?
Answer: The capacity to generate whole plant from any cell/explant is called totipotency.

Question 11. Define micropropagation.
Answer: The method of producing thousands of plants through tissue culture is called micropropagation.

Question 12. Which part of plant is free of virus?
Answer: Apical meristem and axillary meristem.

Short Answer Type Questions

Question 13. In which way traditional farming differs from plant breeding?
Answer: Traditional farming can only yield a limited biomass, as food for humans and animals. Better management practices increased the yield but only to a limited extent. Plant breeding as a technology has helped increase yields to a very large extent.

Question 14. What is the backbone of any breeding programme?
Answer: Genetic variability is the backbone of any breeding programme. In many crops pre-existing genetic variability is available from wild relatives of the crop.

Question 15. How micro-organisms produce high amount of protein in short duration?
Answer: Due to high rate of biomass production and growth.

Question 16. Why production of rice increased in India during the period 1960 to 2000?
Answer: During the period 1960 to 2000, rice production increased from 35 million tonnes to 89.5 million tonnes. This was due to the development of semi-dwarf varieties of rice. Better-yielding semidwarf varieties Jaya and Ratna were developed in India.

Question 17. Discuss the methods of breeding for disease resistance.
Answer: Breeding is carried out by the conventional breeding techniques or by mutation breeding. The conventional method of breeding for disease resistance is that of hybridisation and selection. Other breeding methods that are used are selection amongst somaclonal variants and genetic engineering.

Question 18. Describe plant breeding for the resistance to YMV in bhindi.
Answer: Resistance to yellow mosaic virus in bhindi (Abelmoschus esculentus) was transferred from a wild species and resulted in a new variety of A. esculentus called Parbhani Kranti.

Question 19. Describe the role of biofortification w.r.t. maize, wheat and rice varieties.
Answer: (i) In 2000, maize hybrids that had twice the amount of the amino acids, lysine and tryptophan, compared to existing maize hybrids were developed.
(ii) Wheat variety, Atlas 66 having a high protein content has been used as a donor for improving cultivated wheat.
(iii) It has been possible to develop an iron-fortified rice variety containing over five times as much iron as in commonly consumed varieties.

Question 20. What is the role of IARI for imporving content of vitamins in vegetable crops?
Answer: The IARI, New Delhi has released several vegetable crops that are rich in vitamins, e.g.,
(i) Vitamin A enriched carrots, spinach, pumpkin
(ii) Vitamin C enriched bitter gourd, bathua, mustard, tomato

Question 21. Name three improved characteristics of wheat that helped India to achieve high productivity.
Answer: (i) Semi-dwarf nature
(ii) High yield
(iii) Disease resistance

Question 22. Complete the following table of crop varieties for pest resistance. Crop Variety Insect pest
1. Brassica ______(A) Aphids (rapeseed mustard)
2. ______(B) Pusa Sem 2 Jassids, aphids and fruit borer
3. Okra (Bhindi) Pusa Sawani ______(C)
Answer: (A) – Pusa Gaurav (B) – Flat bean (C) – Shoot and fruit borer

Question 23. Name mineral and protein enriched vegetable crops prepared by IARI.
Answer: Iron and calcium-enriched spinach and bathua and protein enriched beans – broad, lablab, French and garden peas.

Question 24. How is the following varieties of sugarcane different from each other?
(i) Saccharum barberi (ii) Saccharum officinarum
Answer: (i) Saccharum barberi was originally grown in north India but had poor sugar content and yield.
(ii) Saccharum officinarum – It is tropical cane grown in south India having higher sugar content but did not grow well in north India.

Question 25. Why green revolution remained important for India?
Answer: Through green revolution, enough food was produced for the increasing population by development of several high-yielding varieties of wheat, rice etc. from existing farm land.

Question 26. Which one step of plant breeding is very time consuming and why?
Answer: Cross hybridisation among the selected parents. Because desirable characters in hybrid combine usually generates only one in few hundred to thousand crosses.

Question 27. A cow which has 250 kg weight can produce how much protein per day? How does it differ from Methylophilus methylotrophus biomass production?
Answer: 200 g of protein per day. For a given period, 250 g of Methylophilus methylotrophus can produce 25 tonnes of protein while 250 kg cow can produce only 200 g of proetin, so rate of biomass production is very high by the microorganisms.

Question 28. Why tissue culture got developed?
Answer: Tissue culture got developed because traditional breeding technique failed to keep pace for demand as well as failed to provide sufficiently fast and efficient system for crop improvement.

Question 29. Define somatic hybridisation. How it differs from micropropagation?
Answer: To generate hybrid through fusion of two genetically different protoplasts known as somatic hybridisation while micropropagation is method for producing thousand of plant through tissue culture using explant.

Question 30. Fill in the blanks A and B. A B "Classical plant breeding involves of pure lines, followed by to produce plants with desirable traits".
Answer: (A) Hybridization (B) Selection

Long Answer Type Questions

Question 31. Mention the name of main steps involved in breeding a new variety of a crop.
Answer: Main steps involved in plant breeding are :
(i) Collection of variability.
(ii) Evaluation and selection of parents.
(iii) Cross hybridisation among the selected parents.
(iv) Selection and testing of superior recombinants.
(v) Testing, release and commercialisation of new cultivars.

Question 32. (i) What is plant breeding?
(ii) Give two semi-dwarf varieties of rice that were developed in India.
Answer: (i) Plant breeding is purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yield and are disease resistant.
(ii) Jaya and Ratna were developed in India which are better yielding semi-dwarf varieties.

Question 33. Give the name of five varieties bred by hybridisation and selection for disease resistance.
Answer: (i) Wheat – Himgiri
(ii) Brassica – Pusa swarnim (Karan rai)
(iii) Cauliflower – Pusa Shubhra, Pusa Snowball K-1
(iv) Cowpea – Pusa Komal
(v) Chilli – Pusa Sadabahar

Question 34. Describe mutation breeding. Give one example.
Answer: Mutation is the process by which genetic variations are created through changes in the base sequence within genes resulting in the creation of a new character or trait not found in the parental type. It is possible to induce mutations artificially through use of chemicals or radiations (like gamma radiations), and selecting and using the plants that have the desirable character as a source in breeding – this process is called mutation breeding. Example : In mung bean resistance to yellow mosaic virus and powdery mildew were induced by mutations.

Question 35. Give some morphological and biochemical characteristics responsible for insect resistance in host crop plant.
Answer: (i) Hairy leaves in several plants are associated with resistance to insect pests e.g., resistance to jassids in cotton and cereal leaf beetle in wheat.
(ii) In wheat, solid stems leads to non-preference by the stem sawfly.
(iii) Smooth leaved and nectar-less cotton varieties do not attract bollworms.
(iv) High aspartic acid, low nitrogen and sugar content in maize leads to resistance to maize stem borers.

Question 36. (a) What are the sources of resistance gene to insect pest?
(b) Write down the name of variety of rapeseed mustard which show resistance to aphids.
Answer: (a) Sources of resistance genes may be
(i) Cultivated varieties
(ii) Germplasm collections of the crop or wild relatives.
(b) Pusa Gaurav is rapeseed mustard variety which is resistant to aphids.

Question 37. (a) Define biofortification.
(b) What are the objectives of improving nutritional quality in crops?
Answer: (a) Breeding crops with higher levels of vitamins and minerals, or higher protein and healtheir fats is known as biofortification.
(b) It includes objectives of improving :
(i) Protein content and quality.
(ii) Oil content and quality
(iii) Vitamin content
(iv) Micronutrient and mineral content.

Question 38. Write the name of two microorganisms involved in SCP production. How can they be grown on an industrial scale?
Answer: (i) Spirulina
(ii) Methylophilus methylotrophus 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.

Question 39. (a) Define tissue culture and explant.
(b) How can we obtain somaclones?
Answer: (a) Tissue culture : It is the technique of maintaining and growing cells, tissues or organs especially on nutrient medium in suitable containers under controlled environmental conditions. Explant : An excised fragment of tissue or plant part used for raising a whole plant in a tissue culture is called explant.
(b) Micropropagation is a method in which thousands of plants can be obtained through tissue culture. Each of these plants will be genetically identical to the original plant from which they were grown i.e., they are somaclones.

Question 40. (i) Explain the method to obtain the somatic hybrids.
(ii) Why pomato is not popular among common people?
Answer: (a) Scientists have been isolated single cells from plants and after digesting their cell walls have been able to isolate naked protoplast (surrounded by plasma membrane). Isolated protoplasts from two different varieties of plants – each having a desirable characters can be fused to get hybrid protoplast, which can be further grown to form a new plant. These hybrids are called somatic hybrids.
(b) Because this plant did not have all the desired combination of characteristics for its commercial utilization.

Question 41. (a) What are the requirements for making nutrient medium?
(b) How can you obtain virus-free plants?
Answer: (a) The nutrient medium must provide a carbon source such as sucrose and also inorganic salts, vitamins, amino acids and growth regulators like auxins, cytokinins, etc.
(b) We can obtain virus-free plants by meristem culture because apical or axillary meristem is usually free of virus due to high concentration of auxin and rapid rate of cell division.

Question 42. What is the importance of single cell protein? Describe it.
Answer: Conventional agricultural production of cereals, pulses, vegetables, fruits, etc. may not be able to meet the demand of food at the rate at which human and animal population is increasing. The shift from grain to meat diet also creates more demand for cereals as it takes 3-10 kg of grain to produce 1 kg of meat by animal farming. Already more than 25 percent of human population is suffering from hunger and malnutrition. Therefore, alternate sources of proteins for animal and human nutrition have to be searched. One of them is SCP.

Question 43. What is hidden hunger? How can it affect people?
Answer: A far greater number – three billion people – suffer from micronutrient, protein and vitamin deficiencies which is known as hidden hunger because these people cannot afford to buy enough fruits, vegetables, legumes, fish and meat. Their food does not contain essential micronutrients – particularly iron, vitamin A, iodine and zinc, therefore, it increases the risk for disease, reduce lifespan and reduce mental abilities.

Question 44. Describe briefly testing, release and commercialisation steps of plant breeding.
Answer: The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance etc. This evaluation is done by growing these in the research fields and recording their performance under ideal fertiliser application irrigation, and other crop management practices. The evaluation in research fields is followed by tesing the materials in farmer's field, for at least three growing seasons at several locations in the country, representing all the agroclimatic zones. The material is evaluated in comparison to the best available local crop cultivar – a check or reference cultivar.

Question 45. What is green revolution? Describe its contribution on wheat crop.
Answer: The development of several high-yielding varieties of wheat and rice in the mid-1960s, as a result of various plant breeding techniques led to dramatic increase in food production in our country. This phase is often referred to as the green revolution. During the period 1960 to 2000 wheat production increased from 11 million tonnes to 75 million tonnes. This was due to the development of semi-dwarf varieties of wheat. In 1963, several varieties such as Sonalika and Kalyan sona were introduced all over the wheat-growing belt of India.