Question

Answer the following questions :

(i) Define 'predation'.

(ii) Why is predation required in a community of different organisms ? Give any two points.

(iii) Why are predators 'prudent' in nature ?

Hint:

Predation is killing and feeding on prey; it controls prey numbers and keeps diversity; prudent predators avoid exhausting the prey.

Answer 1

Step 1: Define predation (part i):
Predation is an interaction in which one organism, the predator, kills and feeds on another organism, the prey. It moves energy fixed by plants to higher trophic levels.

Step 2: Why predation is needed (part ii):
Point 1: Predators act as conduits for energy transfer from one trophic level to the next.
Point 2: Predators keep prey populations under control. Without them the prey would multiply and damage the habitat, as prickly pear did in Australia.
Another valid point: Predators reduce competition among prey species, so more species can live together. The starfish Pisaster in the rocky intertidal zone of the American Pacific coast shows this.

Step 3: Why predators are prudent (part iii):
If a predator over-exploited its prey, the prey would become extinct and the predator would then starve.
So predators in nature are prudent: they limit their own hunting and leave enough prey to keep the prey population alive.

Final Answer:
(i) Predation: one organism kills and feeds on another. (ii) Any two: energy transfer, control of prey numbers, maintaining species diversity. (iii) Over-exploitation would wipe out the prey and the predator itself.