Genetic drift is change of 

1. gene frequency in same generation 

2. appearance of recessive genes

3. gene frequency from one generation to next 

4. None of the above

Adaptive radiation refers to

1. adaptations due to geographical isolation 

2. evolution of different species from a common ancestor

3. migration of members of a species to different geographical areas

4. power of adaptation in an individual to a variety of environments

When two species of different geneology come to resemble each other as a result of adaptation, the phenomenon is termed

1. divergent evolution

2. micro-evolution

3. co-evolution

4. convergent evolution

Theory of natural selection dwells on 

1. role of environment in evolution

2. natural selection acting on favourable variations

3. changes in gene complex resulting in heritable variations

4. None of the above

Which one of the following options gives one correct example each of convergent evolution and divergent evolution?

The extinct human who lives 100000 to 40000 years ago, in Europe, Asia and parts of Africa, with short stature, heavy eye brows, retreating fore heads, large jaws with heavy teeth, stocky bodies, a lumbering gait and stooped posture was

1. Homo habilis                           

2. Neanderthal human

3. Cro-magnon humans               

4. Ramapithecus

The concept of chemical evolution is based on 

1. crystallization of chemicals

2. interaction of water, air, and clay under intense heat

3. effect of solar radiation on chemicals

4. the possible origin of life by the combination of chemicals under suitable environmental conditions

Which one of the following describes correctly the homologous structures?

1. Organs appearing only in embryonic stage and disappearing later in the adult

2. Organs with anatomical similarities, but performing different functions

3. Organs with anatomical dissimilarities, but performing same functions

4. Organs that have no function now, but had an important function in ancestors

Correct order is [1991]
1. Palaeozoic $\stackrel{ }{\to }$ Archaeozoic $\stackrel{ }{\to }$Coenozoic
2. Archaeozoic $\stackrel{ }{\to }$ Palaeozoic $\stackrel{ }{\to }$ Proterozoic
3. Palaeozoic $\stackrel{ }{\to }$Mesozoic $\stackrel{ }{\to }$ Coenozoic
4. Mesozoic $\stackrel{ }{\to }$Archaeozoic $\stackrel{ }{\to }$ Proterozoic

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

1. NH₃

2. H₂   

3. O₂   

4. CH₄