In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

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

The production of gametes by the parents, formation of zygotes, the F₁ and F₂ plants, can be understood from a diagram called:

1. Punnett square

2. Net square

3. Bullet square

4. Punch square

Sickle cell anaemia is due to:

The probability of four sons to a couple is:

When dominant and recessive alleles express themselves together it is called:
1.  Co-dominance
2.  Dominance
3.  Amphidominance
4.  Pseudo dominance

Independent assortment of genes does not take place when:

A genetic map is one that:

1. Establishes sites of the genes on a chromosome

2. Establishes the various stages in gene evolution

3. Shows the stages during the cell division

4. Shows the distribution of various species in a region

When a cluster of genes shows linkage behaviour they:

1. Do not show a chromosome map

2. Show recombination during meiosis

3. Do not show independent assortment

4. Induce cell division

Which one of the following traits of garden peas studied by Mendel was a recessive feature?

The linkage map of the X-chromosome of fruitfly has 66 units, with yellow body gene (y) at one end and bobbed hair (b) gene at the other end. The recombination frequency between these two genes (y and b) should be:

1. 60%

2. > 50%

3. ≤ 50%

4. 100%