According to Darwin, organic evolution is due to:

1.	Interspecific competition.
2.	Competition within closely related species.
3.	Reduced feeding efficiency in one species due to the presence of interfering species.
4.	Intraspecific competition.

What type of human population is represented by the following age pyramid? 

  
1.  Stable population
2.  Declining population
3.  Expanding population
4.  Vanishing population

The table below gives the populations(in thousands) of ten species(A--J) in four areas (a-d) consisting of the number of habitats given within brackets against each. Study the table and answer the question as follows: 
which area out of a to d shows maximum species diversity? 

1. b

2. c

3. a

4. d

The population of an insect species shows an explosive increase in numbers during the rainy season followed by its disappearance at the end of the season. What does this show?

Geometric representation of age structure is a characteristic of:

1. Biotic community

2. Population

3. Landscape

4. Ecosystem

If the mean and the median pertaining to a certain character of a population are of the same value, the following is most likely to occur:

1. a normal distribution

2. a bi-modal distribution

3. a T-shaped curve

4. a skewed curve

A high density of elephant population in an area can result in:

1. mutualism

2. Intraspecific competition

3. Interspecific completion

4. Predation on one another

Praying mantis is a good example of:

1. Mullerian mimicry

2. Warning colouration

3. Social insects

4. Camouflage

Niche overlap indicates:

A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is: