A gene showing co-dominance has?

A colour-blind man marries a woman with normal sight who has no history of colour blindness in her family. What is the probability of their grandson being colour blind? (consider the grandsons only through son)

1. 0.5

2. 1

3. Nil

4. 0.25

A pleiotropic gene:

The term "linkage" was coined by?

In his classic experiments on pea plants Mendel did not use?

1. Seed color

2. Pod length

3. Seed shape

4. Flower position

In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree: 

1. Autosomal dominant

2. X-linked recessive

3. Autosomal recessive

4. X-linked dominant

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

Alleles are:
1. different phenotype
2. true breeding homozygotes
3. different molecular forms of a gene
4. heterozygotes

How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?

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