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

Which of the following is not usually an adaptation for a parasitic mode of life?

The human liver fluke depends on two intermediate hosts that are:

Flowers and their insect pollinators must undergo co-evolution because:

The pollinator of the fig plant: 

Autecology is the: 

Ecotone is:

1. A polluted area

2. The bottom of a lake

3. A zone of transition between two communities

4. A zone of developing community

Biosphere is:

The ecological niche is:

According to Allen’s Rule, mammals from colder climates have:

1. Shorter ears and longer limbs

2. Longer ears and shorter limbs

3. Longer ears and longer limbs

4. Shorter ears and shorter limbs