Which one of the following symbols and its representation, used in the human pedigree analysis is correct?

1.	= Mating between relatives
2.	= Unaffected male
3.	= Unaffected female
4.	= male affected

A man with blood group 'A' marries a woman with blood group 'B'. What are all the possible blood groups of their offspring?

Select the correct statement from the options given below with respect to the dihybrid cross.

1. Tightly linked genes on the same chromosome show higher recombination

2. Genes for apart on the same chromosomes show very few recombination

3. Genes that are loosely linked on the same chromosomes. Show similar recombination as lightly linked ones

4. Tightly linked genes on the same chromosomes show very few recombination

The movement of a gene from one linkage group to another is called:

Two genes R and y are located very close on the chromosome linkage map on maize plant. When RRYY and rryy genotypes are hybridized, then F₂ segregation will show:

1. Higher number of the recombinant types

2. Segregation with expected 9:3:3:1 ratio

3. Segregation is 3:1 ratio

4. Higher number of parental types

An abnormal human baby with 'XXX' sex chromosomes was born due to:
1. formation of abnormal ova in the mother
2. fusion of two ova and one sperm
3. fusion of two sperms and one ovum
4. formation of abnormal sperms in the father

The dominant epistasis ratio is:

1. 9:3:3:1

2. 12:3:1

3. 9:3:4

4. 9:6:1

If a chiasma forms between the loci of genes A and B in 20% of the tetrads of an individual of genotype AB/ab, the percentage of gametes expected to be Ab is:

1. 40

2. 20

3. 10

4. 5