Which one of the following population interactions is widely used in medical science for the production of antibiotics ?

1. Commensalism
2. Mutualism
3. Parasitism
4. Amensalism

Presence of plants arranged into well-defined vertical layers depending on their height can be seen best in:

1. Tropical Rain Forest

2. Grassland

3. Temperate Forest

4. Tropical Savannah

The principle of competitive exclusion was stated by?

1. C. Darwin

2. G. F. Gause

3. MacArthur

4. Verhulst and Pearl

An association of individuals of different species living in the same habitat and having functional interactions is known as:

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:

1. 15

2. 05

3. zero

4. 10

According to Darwin, organic evolution is due to:

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