Which of the following types of natural selection reduces variation but does not change the mean value?

1.	directional	2.	stabilizing
3.	disruptive	4.	all of these

In modern terms, selection refers to :

An island population faced a natural calamity and the population crashed to only 30 organisms. After some time the number of organisms grew to 5000 but still the threat of extinction is large. This is most likely due to:

The number of individuals expressing the dominant phenotype in a population of 200 is 182. What is the frequency of the dominant allele in this population?

Humans appeared during the epoch:
1. Pleistocene
2. Pliocene
3. Miocene
4. Oligocene

A mutation appears in a sub-population of organisms separated from the other group by in the same large geographical area. This mutation can spread to the other subgroup by:
1. induced muations
2. mutations in the gene pool of the other subgroup
3. mutation pressures
4. crossovers

Though we cannot be certain, what can be the probable reason/s for the sudden disappearance of dinosaurs from the Earth? 

Which of the following pairs of organs do not represent analogous organs?

Darwin got the idea of ‘common descent with modification’ as evolution initially from his observations on:
1. geographic distribution of species
2. fossil records
3. comparative embryology
4. comparative biochemistry

Dinosaurs became extinct during the geological period:
1. Carboniferous
2. Jurassic
3. Cretaceous
4. Tertiary