Affected individuals from the pedigree given below are suffering from albinism, an autosomal recessive disease. Identify the confirmed carrier individuals in their pedigree assuming that the members coming from outside the family are homozygous for the dominant allele

• III-2, III-3, III‐5, III‐6, II‐1, II‐3 and II‐6

• III‐2, III‐3, III‐5, III‐6, II‐2, II‐4, II‐5 and I‐2

• III‐2, III‐3, III‐5, III‐6, II‐2, II‐4 and II‐5

• III‐1, III‐4, III‐7, II‐2, II‐4 and II‐5

A plant of genotype AaBb is selfed. The two genes are linked and are 50 map units apart. What proportion of the progeny will have the genotype aabb?

• 1/2

• 1/4

• 1/8

• 1/16

The base analog 2-aminopurine pairs with thymine, and can occasionally pair with cytosine. The type of mutation induced by 2-aminopurine is

• Transversion

• Transition

• Deletion

• Non-sense

What kind of aneuploid gametes will be generated if meiotic non-disjunction occurs at first division? (‘n’ represents the haploid number of chromosomes)?

• Only n + 1 and n  

• Only n – 1 and n

• Both n + 1 and n – 1  

• Either n +1 or n – 1

Synthesis of normal hemoglobin requires coordinated synthesis of α globin and β globin. Thalassemias are gentic defects perturbed in this coordinated synthesis. Patients suffereing from deficiency of β globin chains (β-thalassemis) could also be due to mutations affecting the biosyntheis of β globin mRNA.

The following statements describe the genesis of non-functional β globin leading to β-thalassemia.

A. Mutation in the promoter region of the β-globin gene.

B. Mutation in the splice junction of the β globin gene.

C. Mutation in the intron I of the β globin gene.

D. Mutations towards the 3’end of the β globin gene that codes for polyadenylation site.

Which of the following combinations is correct?

• A, Band D   

• A, B and C   

• B, C and D   

• C, D and A  

26.

The following figure depicts the relationship between a genetic map for four genes (A, B, C and D) and their corresponding physical map

The following statements are made to explain this relationship

A. More number of recombination events between A and B as compared to B and C.

B. Lesser number of recombination events occur between C and D as compared to B and C.

C. Although the physical distance between A and B is less than that between C and D, and the region between A and B is more recombinogenic.

D. The physical distance between A and B is less than that between and D, and thus the region between A and B is less recombinogenic.

E. Although the physical distance between C and D is more than that between B and C, the region between C and D is less recombinogenic.

F. Although the physical distance between C and D is more than B, the region between C and D is more recombinogenic.

Which statements are correct?

• A and B

• C and E

• D and F

• A, C and E

The ABO blood type in human is under the control of autosomal multiple alleles. Colour blindness is recessive X-linked trait. A male with a blood type A and normal vision marries a female who also has blood type A and normal vision. The couple’s first child is a male who is colour blind and has O blood group. What is the probability that their next female child has normal vision and O blood group?

• 1/4

• 3/4

• 1/8

• 1

The genetic relatedness (r) of an individual to his nephew is 0.25. The alleles that cause uncles to care for nephews will spread, according to Hamilton’s rule, only if the fitness benefit is

• Equal to the cost of care

• More than the cost of care by 25%

• Double the cost of care 

• Four times the cost of care

Figures A and B respectively represent the dideoxy sequencing gels obtained for partial sequences from 5’- ends of a bacterial gene and its mutant (wih a point mutation).

What type of mutation has occurred in the gene?

• Non-sense

• Mis-sense

• Frameshift

• Transversion

The effect of nonsense mutation could be nullified by reversion as well as suppression. Which of the following processes will help to distinguish between the two kinds of revertants?

• Complementation

• Transgenesis

• Test for allelism

• Recombination