A keystone species is:

1.	A common species that has plenty of biomass, yet has a fairly low impact on the community's organisation.
2.	A rare species that has minimal impact on the biomass and on other species in the community.
3.	A dominant species that constitutes a large proportion of the biomass and which affects many other species.
4.	A species that makes up only a small proportion of the total biomass of a community yet has a huge impact on the community's organisation and survival.

Certain characteristic demographic features of developing countries are: 

Biotic and abiotic components form:
1.  Community
2.  Society
3.  Population
4.  Species

The plant having the largest flower is:
1.  Total stem parasite
2.  Epiphyte
3.  Total root parasite
4.  Partial stem parasite

What will happen if the number of organisms increased at a place:
1.  Inter-species competition
2.  Intra-species competition
3.  Both
4.  None

In a population, unrestricted reproductive capacity is called:

1. Biotic potential

2. Fertility

3. Carrying capacity

4. Birth rate

Choose the correct sequence of stages of the growth curve for Bacteria:

1. Leg, Log, stationary, Decline phase

2. Leg, Log, Stationary phase

3. Stationary, Leg, Log, Decline phase

4. Decline, Leg, Log phase

The semilog of per minute growing bacteria is plotted against time. What will the shape of the graph be:

1. Sigmoid

2. Hyperbolic

3. Ascending straight line

4. Descending straight line

Which type of association is found between entomophilous flower and pollinating agent:

1. Mutualism

2. Commensalism

3. Cooperation

4. Co-evolution

Two different species cannot live for a long duration in the same niche or habitat. This is:

1. Allen's law

2. Gloger's rule

3. Competitive exclusion principle

4. Weismann's theory