Organisms and Populations

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

Cuscuta is an example of :

1. Ectoparasitism
2. Predation
3. Endoparasitism
4. Brood parasitism

People who have migrated from the plains to an area adjoining Rohtang Pass about six months back

1. have more RBCs and their haemoglobin has a lower binding affinity to O2
2. are not physically fit to play games like football
3. suffer from altitude sickness with symptoms like nausea, fatigue, etc.
4. have the usual RBC count but their haemoglobin has very high binding affinity to O2.

The logistic population growth is expressed by the equation:

1. dt/dN = Nr ( K-NK )
2. dN/dt = rN ( K-NK )
3. dN/dt = rN ( N-KN )
4. dN/dt = rN

Consider the following statements (A)-(D) each with one or two blanks : (A) Bears go into (1) during winter to (2) cold weather. (B) A conical age pyramid with a broad base represents (3) human population. (C) A wasp pollinating a fig flower is an example of (4) . (D) An area with high levels of species richness is known as (5) . Which of the following options gives the correct fill ups for the respective blank numbers from (1) to (5) in the statements ?

1. (1) - aestivation, (2) - escape, (3) - stable, (4) - mutualism
2. (3) - expanding, (4) - commensalism, (5) - biodiversity park
3. (1) - hibernation, (2) - escape, (3) - expanding, (5) - hot spot
4. (3) - stable, (4) - commensalism, (5) - marsh

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

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