Principles of Inheritance and Variation

Frequency of recombination between gene pairs on same chromosome as a measure of the distance between genes to map their position on chromosome, was used for the first time by

1. Sutton and Boveri
2. Alfred Sturtevant
3. Henking
4. Thomas Hunt Morgan

The phenomenon of pleiotropism refers to

1. Presence of two alleles, each of the two genes controlling a single trait
2. A single gene affecting multiple phenotypic expression
3. More than two genes affecting a single character
4. Presence of several alleles of a single gene controlling a single crossover

Which of the following statements are correct about Klinefelter’s Syndrome? Choose the correct answer from the options given below :

1. C and D only
2. B and E only
3. A and E only
4. A and B only

Broad palm with single palm crease is visible in a person suffering from-

1. Turner’s syndrome
2. Klinefelter’s syndrome
3. Thalassemia
4. Down’s syndrome

Which one of the following symbols represents mating between relatives in human pedigree analysis?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

XO type of sex determination can be found in :

1. Drosophila
2. Birds
3. Grasshoppers
4. Monkeys

Given below are two statements: In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct

Which of the following occurs due to the presence of autosome linked dominant trait?

1. Sickle cell anaemia
2. Myotonic dystrophy
3. Haemophilia
4. Thalassemia

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below :

1. Both (A) and (R) are correct and (R) is the correct explanation of (A)
2. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
3. (A) is correct but (R) is not correct
4. (A) is not correct but (R) is correct

If a colour blind female marries a man whose mother was also colour blind, what are the chances of her progeny having colour blindness?

1. 25%
2. 50%
3. 75%
4. 100%