CBSE Class 12 Biology Worksheet - Principles of Inheritance and Variation : Molecular Basis of Inheretance

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CBSE Class 12 Biology Worksheet - Principles of Inheritance and Variation : Molecular Basis of Inheretance. CBSE issues sample papers every year for students for class 12 board exams. Students should solve the CBSE issued sample papers to understand the pattern of the question paper which will come in class 12 board exams this year. The sample papers have been provided with marking scheme. It’s always recommended to practice as many CBSE sample papers as possible before the board examinations. Sample papers should be always practiced in examination condition at home or school and the student should show the answers to teachers for checking or compare with the answers provided. Students can download the sample papers in pdf format free and score better marks in examinations. Refer to other links too for latest sample papers.

Principles of Inheritance and Variation : Molecular Basis of Inheretance

1. Define heredity, genetics, and inheritance.

2. Why did Mendel select pea plant for his experiments?

3. How did Mendel make sure that the pea plants were true breeding?

4. List the traits in garden pea plant which Mendel studied in his breeding experiments.

5. What is emasculation technique?

6. Define the following terms:

(i) Allele                        (ii) homozygous

(iii) Heterozygous          (iv) Dominant gene

(v) Recessive gene        (vi) Genotype

(vii) Phenotype

7. (a) What is monohybrid cross? How did Mendel carry out this cross? Show with help of Punnet square.

(b) Explain Law of Dominance.

(c) Explain Law of Segregation of gametes.

8. What kind of gametes would be produced by the organisms having the following genotypes?

(i) AaBB

(ii) aaBB

(iii) Aabb

(iv) AaBBCc

9. In human beings, blue eye colour is recessive to brown eye colour. A brown-eyed man has a blueeyed mother.

(a) What is the genotype of the man and his mother?

(b) What are the possible genotypes of his father?

(c) If a man marries a blue-eyed woman, what are the possible genotypes of their offspring?

10. What is test cross? Give its use.

11. In dogs black coat colour is dominant over white. What coloured dog will you choose to breed a given black dog to find its genotype? What is this type of cross known as?

12 (a) What is incomplete dominance? Describe one example of incomplete dominance.

(b) What is the difference between dominance and incomplete dominance?

13. What is multiple allelism? Give its suitable example.

14. What is codominance? Give suitable example.

15. How is codominance different from incomplete dominance?

16 (a) Describe briefly the dihydrid cross conducted by Mendel.

(b) State the Law of Independent Assortment.

17. State the reasons for which the published work for Mendel remained unrecognized for several years.

18. Who proposed the chromosome theory of inheritance? Give the salient features of this theory.

19. Why did Morgan select Drosophilia for his experiments?

20. What is linkage? Describe briefly the two types of linkage.

21. State the relationship between linkage and crossing over.

22. Briefly mention the contribution of T.H.Morgan in genetics.

23. What is the role of Henking in discovery of X-chromosome?

24. What are autosomes and sex chromosomes?

25. discuss briefly different types of sex determination

(a) XO-XX type      (b) XX-XY type     (c) ZW-ZZ type

26. What is male heterogamety and female heterogamety?

27. Define mutation and mutagens.

28. What is point mutation and chromosomal mutations?

29. What is pedigree analysis? What are the symbols used in such an analysis?

30. Give the use of pedigree analysis.

31. What is haemophilia? Why do generally only human males suffer from haemophilia? Can women also suffer? Explain

32. How is sickle cell anaemia caused? What are its symptoms?

33. Write short note on Phenylketouria.

34. What is aneuploidy? Differentiate between trisomic and haploid condition.

CBSE Class 12 Biology Worksheet - Principles of Inheritance and Variation : Molecular Basis of Inheretance.


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