Darwin believed that certain parts of the body get larger and more complex through the generations because they :

1. are used more extensively than other parts 

2. contribute to greater reproductive success

3. are pre-determined to do so 

4. are most similar to God's perfection 

The wings of a bird and that of an insect are:

1. Analogous structures

2. Homologous structure

3. Vestigial structures

4. Useless structures

Directional selection favours:

(1) Both extremes of a trait

(2) Intermediate form of a trait

(3) Environmental differences

(4) One extreme form over the other extreme form and over intermediate forms of the trait

Most often the factor that initiates the speciation of two populations is:

(1) Geographic isolation

(2) Inability of the gametes to fuse

(3) Different courtship behaviours

(4) Different copulatory organs

The oldest fossils resemble:

1. Amoeba

2. Red algae

3. Heterotrophic bacteria

4. Autotrophic bacteria

Reptilian ancestors of the mammals were the :-
1. Therapsids
2. Thecodonts
3. Pterosaurs
4. Plesiosaurs
 

Given below is the representative evolutionary history of vertebrates through geological periods. A, B, C, and D respectively are:

Karn & Penrose showed that birth weight follows a normal distribution, that mortality for newborns is greater for those either under-or over-weight, and that the mean birth weight (7 lbs) coincides with that showing minimum mortality. The type of natural selection operating here is shown by the graph :

1. (a)

2. (b)

3. (c)

4. Both (a) and (b)

The following two plants exhibit :

1. Analogous organs

2. Vestigial organs

3. Rudimentary organs

4. Homologous organs

In the apparatus of Urey and Miller experiment, the gases [G] contained in the flask are :

1. Methane, Carbon dioxide, Ammonia and Water vapour
2. Methane, Hydrogen cyanide, Ammonia and Water vapour
3. Methane, Ammonia, Hydrogen and Water vapour
4. Carbon dioxide, Oxygen, hydrogen and ammonia