If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

1.	50%	2.	25 %
3.	100%	4.	no chance

A man whose father was colour blind marries a woman who had a colour blind mother and a normal father. What percentage of male children of this couple will be colour blind?

1. 25%

2. 0%

3. 50%

4. 75%

Sickle cell anaemia is:

In hexaploid wheat, the haploid (n) ar basic (x) numbers of chromosomes are:

1. n=7 and x=21

2. n=21 and x=21

3. n=21 and x=14

4. n=21 and x=7

Inheritance of skin colour in humans is an example of:

1. chromosomal aberration

2. point mutation

3. polygenic inheritance

4. codominance

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

1. higher number of the recombinant types

2. segregation in the expected 9:3:3:1 ratio

3. segregation in a 3:1 ratio

4. higher number of the parental types

In pea plants, yellow seeds are dominant to green. If a heterozygous yellow-seeded plant is crossed with a green-seeded plant, what ratio of yellow and green-seeded plants would you expect in F1generation?

1. 50:50

2. 9:1

3. 1:3

4. 3:1

Which one of the following is the most suitable, medium for culture of Drosophila melanogaster?

1. Moist bread

2. Agar agar

3. Ripe banana

4. Cow dung

Phenotype of an organism is the result of:

1. mutations and linkages

2. cytoplasmic effects and nutrition

3. environmental changes and sexual dimorpgism

4. genotype and environment interactions