Sickle cell anaemia has not been eliminated from African population as
1. It is controlled by dominant genes
2. It is controlled by recessive genes
3. It is not a fatal disease
4. It provides immunity against malaria

The set of all genes, or genetic information, in a unit of evolution is called the :
1. genotype
2. polymorphism
3. multiple allelism
4. gene pool

Viviparity is considered to be more evolved because:

1. the young ones are left on their own

2. the young ones are protected by a thick shell

3. the young ones are protected inside the mother's body and are looked after they are born leading to more chances of survival

4. the embryo takes a long time to develop