Organisms and Populations · Question 44

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

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. Keoladeo National Park
2. Meghalaya
3. Corbett National Park
4. Western Ghat

A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is :

1. Commensalism
2. Amensalism
3. Ectoparasitism
4. Symbiosis

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. 10
4. zero

The age pyramid with broad base indicates :

1. high percentage of young individuals
2. high percentage of old individuals
3. a stable population
4. low percentage of young individuals

Which one of the following is not a parasitic adaptation ?

1. Loss of digestive organs
2. Loss of unnecessary sense organs
3. Development of adhesive organs
4. Loss of reproductive capacity

Benthic organisms are affected most by :

1. Surface turbulence of water
2. Water-holding capacity of soil
3. Light reaching the forest floor
4. Sediment characteristics of aquatic ecosystems