Which was absent in the atmosphere at the time of origin of life?

1. NH₃

2. H₂   

3. O₂   

4. CH₄

Homeostasis is 

1. tendency to change with change in environment

2. tendency to resist change

3 disturbance in regulatory control

4. plants and animals extracts used in homeopathy

Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution?

1. Discontinuous variations

2. Parasites and predators as natural enemies

3. Survival of the fittest

4. Struggle for existence

In recent years, DNA sequences (nucleotide sequence) of mtDNA and Y-chromosomes were considered for the study of human evolution, because

1. they can be studied from the samples of fossil remains

2. they are small and, therefore, easy to study

3. they are uniparental in origin and do not take part in recombination

4. their structure is known in greater detail

Which one is irrelevant to evolution of man? 

1. Perfection of hand for tool making

2. Change of diet from hard nuts/roots to soft food

3. Increased ability to communicate or develop community behaviour

4. Loss of tail

Study of fossils is 

1. palaeontology

2. herpetology

3. saurology

4. organic evolution

Genetic drift operates only in

1. smaller populations

2. larger populations

3. Mendelian populations

4. island populations

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

1. analogous and vestigial organs

2. homologous organs only

3. homologous and analogous organs 

4. homologous and vestigial organs

The earliest fossil form in the phylogeny of horse is

1. Merychippus

2. Mesohippus

3. Eohippus

4. Equus

Which is not a vestigial part in humans ? 

1. Segmental muscles of abdomen

2. Finger nails

3. Third molar

4. Coccyx