Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	Temperature is most important ecologically relevant environmental factor.
Reason (R):	Temperature affects the kinetics of the enzymes.

 In the light of the above statements, choose the most appropriate answer from the options given below :

1.	Both (A) and (R) are true and (R) is the correct explanation of (A).
2.	Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.	(A) is true but (R) is false.
4.	Both (A) and (R) are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Desert lizards are able to keep their body temperature fairly constant by:
1. Physiological means
2. Anatomical means
3. Biochemical means
4. Behavioral means

When Darwin spoke of the struggle for existence, he was convinced that a potent force in organic evolution is:

MacArthur showed that five closely related species of warblers living on the same tree were able to avoid competition and co-exist due to:
1. Behavioral differences in their foraging activities.
2. Pre-zygotic reproductive isolation mechanisms
3. Physiological differences in acclimatization
4. Gene differentiation

The human liver fluke depends on two intermediate hosts that are:
1. A crustacean and a fish
2. A snail and a fish
3. An echinoderm and a fish
4. Fishes of two different species

Formation of tropical forests needs mean annual temperature and mean annual precipitation as:

1. 18 – 25 °C and 150 – 400 cm

2. 5 – 15 °C and 50 – 100 cm

3. 30 - 50°C and 100 – 150 cm

4. 5 – 15 °C and 100 – 200 cm

Which of the following forest plants controls the light conditions at the ground?

1. Lianas and climbers

2. Shrubs

3. Tall trees

4. Herbs