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Biology · Class 12 Science

Ch 8Improvement in Food Production — Class 12 Biology, concept-first.

India's population has grown from about 350 million at Independence to well over a billion today, and even a well-managed farm cannot go on raising food output indefinitely by simply bringing more land under the plough -- most of the land that can be usefully cultivated is already in use.

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Key concepts

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Plant Breeding

Plant breeding is the deliberate, purposeful manipulation of plant species to create new types that are better suited to cultivation, give higher yield and resist disease.

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Chapter contents

The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.

8.1

Introduction to Improvement in Food Production

India's population has grown from about 350 million at Independence to well over a billion today, and even a well-managed farm cannot go on raising food output indefinitely by simply bringing more lan…

8.2

Plant Breeding: Meaning and Objectives

Plant breeding is the purposeful, scientifically guided improvement of crop plants -- applying genetic principles to develop plant types that yield more, resist disease and adverse conditions better,…

8.3

Hybridization, Selection and Release of New Varieties

Once a plant breeding programme's objectives have been set, the actual work proceeds through a connected sequence of steps, each depending on the one before it.

8.4

Achievements of Plant Breeding in India

India's own history of plant breeding since Independence illustrates every objective described in the previous sections being put into practice, and is the direct ancestor of the country's Green Revol…

8.5

Tissue Culture and the Principle of Totipotency

Classical plant breeding, powerful as it is, works only through sexual reproduction and takes several plant generations -- often many years -- to produce and stabilise a new variety.

8.6

Micropropagation

Micropropagation is the practical application of totipotency to solve a very ordinary problem: how to multiply a single superior plant -- one that combines high yield, disease resistance and good qual…

8.7

Somatic Hybridization and Somaclonal Variation

Tissue culture also makes possible two further routes to genetically novel plants that classical, seed-based cross-hybridization (described earlier in this chapter) cannot achieve on its own.

8.8

Single Cell Protein (SCP)

Improving crop plants, whether by breeding or tissue culture, is one route to feeding a growing population; producing more protein without growing a crop plant at all is a second, complementary route,…

Summary

A concise recap of the chapter: plant breeding (the purposeful, scientifically guided improvement of crop plants for higher yield, quality and stress resistance, carried out through germplasm collecti…

Very Short Answer Questions

+Show 6 questions6 questions
  1. Q9Define plant breeding in one or two sentences.Free
  2. Q10State any two objectives of a plant breeding programme.Free
  3. Q11Define totipotency, naming the scientist who first proposed the concept.Preview
  4. Q12What is meant by an 'explant' in plant tissue culture?Preview
  5. Q13Define Single Cell Protein (SCP), naming one organism commonly used to produce it.Preview
  6. Q14What is somaclonal variation?Preview

Short Answer Questions

+Show 6 questions6 questions
  1. Q15Describe, in sequence, the steps involved in a classical plant breeding programme, from the collection of genetic variability to the release…Free
  2. Q16Explain the technique of cross-hybridization in plant breeding, including the purpose of emasculation and bagging.Free
  3. Q17With two named examples, describe how plant breeding has been used in India to develop crop varieties resistant to disease or of improved yi…Preview
  4. Q18Explain the principle of totipotency and describe, in outline, how a complete plant can be regenerated from a small explant in tissue cultur…Preview
  5. Q19Explain the process and chief applications of micropropagation.Preview
  6. Q20Explain what is meant by somatic hybridization (protoplast fusion), and state one reason it is useful in crop improvement when sexual hybrid…Preview

Long Answer Questions

+Show 4 questions4 questions
  1. Q21Give a detailed account of a classical plant breeding programme, describing each step (germplasm collection, evaluation and selection of par…Free
  2. Q22Describe plant tissue culture in detail, covering the principle of totipotency, the composition of the nutrient culture medium, and the tech…Free
  3. Q23Discuss somatic hybridization (protoplast fusion) and somaclonal variation as tools of modern plant breeding, explaining how each differs fr…Preview
  4. Q24Discuss Single Cell Protein (SCP) as an alternative source of protein: define it, name organisms commonly used to produce it, and explain wh…Preview

Sample & Board Papers

Sample papers and previous-year board questions for this subject.

+Show 11 questions11 questions
  1. Q1Virus-free plants can be obtained by (a) culturing shoot apex (b) treating the plants with Bordeaux mixture (c) giving antibiotic treatment…Preview
  2. Q2Which plant breeding method is used by human from ancient time? (a) Hybridization (b) Selection (c) Mutation (d) None of thesePreview
  3. Q3What do you mean by tissue culture? What is micropropagation? (2+1)Preview
  4. Q4Mention the advantages of poultry farm. **OR** Mention one high milk producing breed of cattle. Mention the scientific name of honeybee spec…Preview
  5. Q5Mention the objectives of Plant Breeding. Give scientific name of a minor carp. (2+1) **OR** Write a short note on role of bacteria in indus…Preview
  6. Q6What is Heterosis?Preview
  7. Q7Describe the plant tissue culture process in brief.Preview
  8. Q8Which one of the following is an exotic fish? (a) Labeo rohita (b) Cyprinus carpio var. communis (c) Tilapia massambica (d) Both (b) and (c)Preview
  9. Q9What is Biofortification?Preview
  10. Q10Write the differences between Pure line selection and Mass selection method of plant breeding based on the following points : i) type of pol…Preview
  11. Q11i) What do you mean by biofortification? ii) How are biofortified maize and wheat considered nutritionally improved?Preview

More questions

+Show 8 questions8 questions
  1. Q1Plant breeding is best defined as: (a) The natural, unaided evolution of crop plants over geological time (b) The purposeful improvement of…Free
  2. Q2Which of the following is NOT a genuine objective of a plant breeding programme? (a) Higher yield per unit area (b) Resistance to biotic str…Free
  3. Q3Which of the following correctly represents, in order, the FIRST TWO steps of a classical plant breeding programme? (a) Testing and release…Free
  4. Q4In a plant breeding cross, the removal of anthers from a bisexual flower bud before they dehisce -- a step called emasculation -- is carried…Preview
  5. Q5The wheat variety Himgiri, developed through hybridization and selection, is notable chiefly for its: (a) Resistance to leaf and stripe rust…Preview
  6. Q6The inherent capacity of a single plant cell (or a small explant) to regenerate, under suitable culture conditions, into a complete new plan…Preview
  7. Q7The chief practical advantage of micropropagation over raising new plants from seed is that it: (a) Introduces new genetic variation into ev…Preview
  8. Q8Which of the following organisms is commonly cultured on an industrial scale as a source of Single Cell Protein (SCP)? (a) Spirulina, a blue…Preview