12th Standard Bio-Zoology English Medium Principles Of Inheritance and Variation Reduced Syllabus Important Questions With Answer Key 2021

12th Standard

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Biology

Time : 01:00:00 Hrs
Total Marks : 100

Multiple Choice Questions

15 x 1 = 15
1. Haemophilia is more common in males because it is a

(a)

Recessive character carried by Y-chromosome

(b)

Dominant character carried by Y-chromosome

(c)

Dominant trait carried by X-chromosome

(d)

Recessive trait carried by X-chromosome

2. What can be the blood group of offspring when both parents have AB blood group?

(a)

AB only

(b)

A, B and AB

(c)

A, B, AB and O

(d)

A and B only

3. If the childs blood group is ‘O’ and fathers blood group is ‘A’ and mother’s blood group is ‘B’ the genotype of the parents will be

(a)

IA IA and IB Io

(b)

IA Io and IB Io

(c)

IA Io and IoIo

(d)

IoIo and IB IB

4. Mangolism is a genetic disorder which is caused by the presence of an extra chromosome number

(a)

20

(b)

21

(c)

4

(d)

23

5. “Universal Donor” and “Universal Recipients” blood group are _____and_______respectively

(a)

AB, O

(b)

O, AB

(c)

A, B

(d)

B, A

6. The ABO blood group was discovered by ________.

(a)

Sturli

(b)

Decastelle

(c)

Landsteiner

(d)

Alexander wiener

7. The lygaeus type (XX - XY) type of sex determination is seen in ______

(a)

Fishes

(b)

Chickens

(c)

Human beings

(d)

Gypsy moth

8. __________ was first reported by John Cotto.

(a)

Erythroblastosis foetalis

(b)

Haemophilia

(c)

Colour blindness

(d)

Haplodiploidy

9. Depending on position of centromere and relative length of two arms human chromosomes can be classified into ________ type.

(a)

2

(b)

3

(c)

4

(d)

5

10. The gene responsible for ________ is inherited as an autosomal recessive lethal gene in man

(a)

Huntington's chorea

(b)

Albinism

(c)

Colourblindness

(d)

Phenylketonuria

11. _________ is an inborn error of metabolism caused due to autosomal recessive gene.

(a)

Thalassemia

(b)

Albinism

(c)

Phenylketonuria

(d)

Huntington's chorea

12. The allele Io is called _______

(a)

Dominant allele

(b)

null allele

(c)

null allele

(d)

epistatic allele

13. Which one of the following cannot be explained on the basis of Menders Law of Dominance?

(a)

The discrete unit controlling a particular character is called a factor

(b)

Out of one pair factors one is dominant and the other recessive

(c)

Alleles do not show any blending and both the characters recover as such in F2 generation

(d)

Factors occur in pairs

14. ABO blood groups in humans are. controlled by the gene I, It has three alleles - IA, IB and i. Since there are three different alleles) six different genotypes are possible. How many phenotypes can occur?

(a)

Three

(b)

One

(c)

Four

(d)

Two

15. Assertion (A): On diagnosis, Ramu is reported to have underdeveloped testis and gynaecomastia.
Reason (R): His karyotype reveals XXY condition

(a)

A is right but R is wrong

(b)

R explains A

(c)

Both A and R are wrong

(d)

Both and R are right but R is not the correct explanation of A

16. 2 Marks

10 x 2 = 20
17. What is haplodiploidy?

18. What is criss-cross inheritance?

19. What is Rh factor or Rh antigen?

20. Name the discoverers of antigen A, B, and AB.

21. State Wiener Hypothesis on Rb-factor.

22. Define Barr body.

23. Observe the symbol used in pedigree analysis and give the proper terms they represent.

24. Complete the equation.
(a) Phenylalanine $\underrightarrow { A }$ Tyrosine
(b) DOPA $\underrightarrow { B }$ Melanin

25. Write a note on Huntington's chorea.

26. Write the symptoms of Patau's syndrome.

27. 3 Marks

10 x 3 = 30
28. Differentiate Intersexes from Supersexes

29. Explain the genetic basis of ABO blood grouping man.

30. Explain male heterogamety

31. Give an account of genetic control of Rh factor.

32. What is karyotyping?

33. Draw the symbols for
(a) Mating (b) Dizygotic twins.

34. What is the chemical reaction that is affected in people suffering from Albinism?

35. Role of Y- chromosome is crucial for maleness - Justify.

36. The following table shows the genotypes for ABO blood grouping and this phenotypes. Complete the table by filling the gaps.

 S.No Genotype Phenotype 1 IAIA A 2 ? A 3 ? AB 4 IOIO ?
37. Write the causes and the differences between Haemophilia and Thalassemia

38. 5 Marks

7 x 5 = 35
39. Explain the mode of sex determination in honeybees.

40. What are the applications of Karyotyping?

41. Explain the inheritance of sex linked characters in human being.

42. Comment on the methods of Eugenics.

43. Write a note on thalassemia.

44. Write a note on any 2 Mendelian disorders occurring in human beings.

45. Explain in detail about Erythroblastosis foetalis.