Organisms and Populations

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

Large woody vines are more commonly found in

1. Mangroves
2. Tropical rainforests
3. Alpine forests
4. Temperate forests

Consider the following four conditions (a – d) and select the correct pair of them as adaptation to environment in desert lizards. The conditions : (a) burrowing in soil to escape high temperature (b) losing heat rapidly from the body during high temperature (c) bask in sun when temperature is low (d) insulating body due to thick fatty dermis

1. (c), (d)
2. (b), (d)
3. (a), (c)
4. (a), (b)

Which one of the following is categorised as a parasite in true sense?

1. The female Anopheles bites and sucks blood from humans
2. Head louse living on the human scalp as well as laying eggs on human hair
3. The cuckoo (koel) lays its eggs in crow's nest
4. Human foetus developing inside the uterus draws nourishment from the mother

Which one of the following is most appropriately defined?

1. Parasite is an organism which always lives inside the body of other organism and may kill it.
2. Host is an organism which provides food to another organism.
3. Amensalism is a relationship in which one species is benefited whereas the other is unaffected
4. Predator is an organism that catches and kills other organism for food.