Match List-I with List-II.
| List-I (Organism) | List-II (Defence against its predators) |
| (A) Monarch butterfly | (I) Thorns, the most common morphological means of defence |
| (B) Calotropis | (II) Highly poisonous cardiac glycosides |
| (C) Acacia | (III) Cryptic colouration (camouflage) to avoid being detected easily |
| (D) Some species of insects and frogs | (IV) A special chemical, acquired at the caterpillar stage by feeding on a poisonous weed, that makes it highly distasteful |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A-IV, B-II, C-I, D-III
Prey species have evolved defences to lessen the impact of predation. Some animals avoid being seen by their colour, some are poisonous or distasteful, and plants, which cannot run away from their predators, use thorns and chemicals.
(A) Monarch butterfly — this matches (IV) A special chemical, acquired at the caterpillar stage by feeding on a poisonous weed, that makes it highly distasteful. The chemical stays in the body of the adult butterfly, so birds that try to eat it find it highly distasteful and leave it alone.
(B) Calotropis — this matches (II) Highly poisonous cardiac glycosides. This weed of abandoned fields uses a chemical defence. Because of these glycosides, cattle and goats do not browse on it.
(C) Acacia — this matches (I) Thorns, the most common morphological means of defence. Thorns are a structural (morphological) defence, seen in Acacia and Cactus.
(D) Some species of insects and frogs — this matches (III) Cryptic colouration (camouflage) to avoid being detected easily. Their colour blends with the background, so the predator does not spot them easily.
NCERT Extract:
Predation – “… Prey species have evolved various defenses to lessen the impact of predation. Some species of insects and frogs are cryptically-coloured (camouflaged) to avoid being detected easily by the predator. Some are poisonous and therefore avoided by the predators. The Monarch butterfly is highly distasteful to its predator (bird) because of a special chemical present in its body. Interestingly, the butterfly acquires this chemical during its caterpillar stage by feeding on a poisonous weed.”
Predation – “… Thorns (Acacia, Cactus) are the most common morphological means of defence. Many plants produce and store chemicals that make the herbivore sick when they are eaten, inhibit feeding or digestion, disrupt its reproduction or even kill it. You must have seen the weed Calotropis growing in abandoned fields. The plant produces highly poisonous cardiac glycosides and that is why you never see any cattle or goats browsing on this plant.”