Variation in gene frequencies within populations can occur by chance rather than by natural selection. 
This is referred to as:

1. Genetic drift

2. Random mating

3. Genetic load

4. Genetic flow

In the case of peppered moth (Biston betularia), the black-coloured form became dominant over the light-coloured form in England during the industrial revolution. This is an example of:

Select the correct statement from the following:

The finches of the Galapagos islands provide evidence in favour of:

1. special creation

2. evolution due to mutation

3. retrogressive evolution

4. biogeographical evolution

An important evidence in favour of organic evolution is the occurrence of:

1. homologous and vestigial organs

2. analogous and vestigial organs

3. homologous organ only

4. analogous organ only

Variations caused by mutation, as proposed by Hugo de Vries, are:

In a species, the weight of a newborn ranges from 2 to 5 kg. 97% of the newborns with an average weight between 3 to 3.3 kg survive whereas 99% of the infants born with weights from 2 to 2.5 kg or 4.5 kg to 5 kg die. Which type of selection process is taking place?

For the stability of the organic compounds, Oparin opined that probably:
1. UV radiation never reached the surface of the primeval Earth

2. the primitive Earth was in a molten state

3. the primitive Earth atmosphere was reducing rather than oxidizing

4. plenty of energy sources were available for chemical reactions to occur

Both Charles Darwin and A.R.Wallace were influenced by the:
1. writings of J.B.S.Haldane on the origin of life
2. findings of Urey and Miller experiments
3. findings on the Galapagos Islands
4. essay on human population by T.R.Malthus