Organisms and Populations

Mycorrhizae are the example of :

1. Fungistasis
2. Antibiosis
3. Mutualism
4. Amensalism

It is much easier for a small animal to run uphill than for a large animal, because -

1. The efficiency of muscles in large animals is less than in the small animals
2. Smaller animals have a higher metabolic rate
3. It is easier to carry a small body weight
4. Small animals have a lower O2 requirement

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 death rate is greater than birth rate.
2. When N/K equals zero.
3. When N/K is exactly one.
4. When N nears the carrying capacity of the habitat.

Gause's principle of competitive exclusion states that -

1. Larger organisms exclude smaller ones through competition
2. More abundant species will exclude the less abundant species through competition
3. Competition for the same resources excludes species having different food preferences
4. No two species can occupy the same niche indefinitely for the same limiting resources

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

1. Small number of progeny with small size
2. Small number of progeny with large size
3. Large number of progeny with small size
4. Large 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. parasitism
2. commensalism
3. mutualism
4. amensalism

The principle of competitive exclusion was stated by

1. MacArthur
2. G. F. Gause
3. Verhulst & Pearl
4. C. Darwin

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

1. Competition
2. Predation
3. Mutualism
4. Parasitism

The following graph depicts changes in two populations (A and B) of herbivores in a grassy field. A possible reason for these changes is that: [figure]

1. Population B competed more successfully for food than population A
2. Population A consumed the members of population B
3. Both plant populations in this habitat decreased
4. Population A produced more offspring than population B

Most animals are tree dwellers in a:

1. temperate deciduous forest
2. tropical rain forest
3. coniferous forest
4. thorn woodland