Principles of Inheritance and Variation

Class 12th Biology Chapter 5 Objective in English : Here you can find class 12th biology Objective questions for board exam 2024. Principles of Inheritance and Variation objective questions is very important for board exam 2023 – 2024. mcq questions for class 12th biology chapter 5 in english. important question website

12th Biology Chapter 5 Objective Questions in English

1. An individual with two identical alleles is : 

(A) Hybrid 

(B) Dominant 

(C) Homozygous

(D) Heterozygous

2. Law of segregation is also known as:

(A) Law of dominance

(B) Law of independent assortment

(C) law of purity of gametes

(D) none of these

3. In human blood group AB :

(A) antibodies are present

(B) antibodies are absent

(C) antibody a is present

(D) antibody b is present

4. ZZ  ⁄  ZW type of sex determination is seen in : 

(A) platypus 

(B) snails

(C) cockroach 

(D) peacock

5. Triticum aestivum is : 

(A) Triploid 

(B) Tetraploid

(C) Hexaploid 

(D) Diploid

6. Tumer’s syndrome will contain how many chromosomes ? 

(A) 45 

(B) 46

(C) 47 

(D) None of these

7. The term “Genetics’ was proposed by:

(A) Mendel

 (B) Morgan

(C) Beteson 

(D) Johansen

8. What is the number of chromosomes in Down’s syndrome ? 

(A) 46 

(B) 47

(C) 48 

(D) None of these

9. ‘ABO’ blood group in human beings shows : 

(A) incomplete dominance

(B) multiple allele

(C) co-dominance 

(D) both (B) and (C)

10. How many characters were studied by Mendel ? 

(A) Five 

(B) Four

(C) Seven 

(D) Three

11. The phenotypic ratio for F2generation in Incomplete dominance is : 

(A) 3:1 

(B) 2 : 2

(C) 1:2:1 

(D) None of these

12. Sickle cell is : 

(A) An autosomal dominant trait 

(B) Occurrence of Sickle like nucleated RBCs.

(C) Change in a single base pair of DNA

(D) None of these

13. What is considered as father of genetics ? 

(A) Hugo de Vries

(B) Morgan

(C) Mendel 

(D) Darwin

14. A person suffering from colour blindness cannot recognise : 

(A) red and yellow colours

(B) red and green colours 

(C) blue and green colours

(D) none of these

15. Mendel proposed : 

(A) law of linkage 

(B) 10% energy law

(C) laws of inheritance

(D) none of these

16. Which of the following Mendel’s Law is not universal ? 

(A) Law of Dominance

(B) Law of Segregation

(C) Law of Independent Assortment

(D) None of these

17. Loss of Melanin pigment cause for : 

(A) Colourblindness

(B) Depigmentation 

(C) Phenyl Ketoneuria

(D) Alkaptoneuria

18. Mendel selected : 

(A) Gram 

(B) Pinus

(C) Tomato 

(D) Garden pea

19. Mendal was born in :

(A) 17th century 

(B) 18th century

(C) 19th century 

(D) 8th century

20. First geneticist/father of genetics was

(A) de Vries

(B) Mendel

(C) Darwin 

(D) Morgan

21. A normal vision female whose father is colour-blind marries a normal vision male. What would be the probability of her sons and daughters to be colour blind?

(A) 25% sons colour blind and all daughters with phenotypically normal vision

(B) 50% sons colour blind and 50% daughter normal

(C) 50% sons colour blind and 50% daughter colour blind

(D) All sons normal and 50% colour blind daughter.

22. A child with blood group ‘O’ has ‘B’ blood group type father then the father has geno type of: 

(A) 1°T° 

(B) I°IB



23. Human blood group O has : 

(A) antigen absent

(B) antibody absent

(C) antigen present

(D) antibody A present

24. Purine base on DNA molecule has : 

(A) A and C 

(B) C and T

(C) A and G 

(D) none of these

25.  How many nitrogen base pairs are present in a complete rotation (twist) of B-DNA: 

(A) 5 

(B) 10

(C) 15 

(D) 20

26. Bacteria has : 

(A) Plasmid DNA 


(C) Both ‘A’ and ‘B’ 

(D) None of these

27. Which one is phenotypic ratio of Monohybrid cross? 

(A) 1:2:1 

(B) 3:1

(C) 9:3:3:1 

(D) None

28. Chromosome number in human being (male) is: 

(A) 44 + XX 

(B) 44 + xy

(C) 46 + xy 

(D) 46 + XX

29. Mutations can be induced with 

(A) Ethylene 

(B) Gamma radiations

(C) Infra-red radiations


30. Ultimate source of Variations is : 

(A) Mitosis 

(B) Meiosis

(C) Fertilization 

(D) Mutations

31. The human chromosome with highest and least number of genes are : 

(A) Chromosome 21 and Y

(B) Chromosome 1 and X

(C) Chromosome 1 and Y

(D) Chromosome X and Y

32. Sickle cell anaemia shows : 

(A) Epistrasis 

(B) Co-dominance

(C) Pleiotropy 

(D) Incomplete dominance

33. Which of the following Blood Group is Universal donar ? 

(A) A 

(B) B

(C) AB 

(D) O

34. 1:2:1 Ratio is a cross show : 

(A) Dominance 

(B) Incomplete Dominance

(C) Linkage 

(D) None of these

35. Chromosome number in human female (Woman) is : 

(A) 44 + XX 

(B) 44 + XY

(C) 44 + YY 

(D) None

36. Genotypic Ratio of Monohybrid cross is :

(A) 1:2:1 

(B) 3:1

(C) 9:3:3:1 

(D) None of these

37. Brewery is concerned with: 

(A) Saccharomyces

(B) Protozoans

(C) Pteridophytes 

(D) Marsupials

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