Mycorrhizae are the example of

(1) fungistasis                 

(2) amensalism

(3) antibiosis                   

(4) mutualism

Which of the following is correct for r-selected species?

(1) Large number of progeny with small size

(2) Large number of progeny with large size

(3) Small number of progeny with small size

(4) Small number of progeny with large size

If '+' sign is assigned to beneficial interaction, '-' sign to detrimental and '0' sign to neutral interaction, then the population interaction represented by '+' '-' refers to

(1) Mutualism

(2) Amensalism

(3) Commensalism

(4) Parasitism

When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt = rN(1-N/K)

(1) when N nears the carrying capacity of the habitat

(2) when N/K equals zero

(3) when death rate is greater than birth rate

(4) when N/K is exactly one

Gause's principle of competitive exclusion states that
1. Competition for the same resources excludes species having different food preferences
2. No two species can occupy the same niche indefinitely for the same limiting resources
3. Larger organisms exclude smaller ones through competition
4. More abundant species will exclude the less abundant species through competition

An association of individuals of different species living in the same habitat and having

functional interactions is.

1. ecological niche

2. biotic community

3. ecosystem

4. population

In which of the following interactions both partners are adversely affected?

(1) Competition

(2) Predation

(3) Parasitism

(4) Mutualism

Most animals are tree dwellers in a 

1. coniferous forest

2. thorn woodland

3. temperate deciduous forest

4. tropical rainforest

Just as a person moving from Delhi to Shimla to escape the heat for the duration of hot

summer, thousands of migratory birds from Siberia and other extremely cold Northern

regions move to

1. Western Ghat               

2. Meghalaya

3. Corbett National Park     

4. Keoladeo National Park

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. 10         

2. 15           

3. 05           

4. zero