Question

The prey of herbivores has certain defence mechanisms to protect themselves from their predators. Which among the following are defence mechanisms developed by the prey species of herbivores?

A. Presence of thorns
B. Production of alkaloids
C. Production of cardiac glycosides

• A. Only A
• B. A, B and C
• C. A and C
• D. B and C

Answer 1

The correct option is B A, B and C

Predation is a type of interaction in which the predator eats another organism called prey.

If over-exploited by predators, the prey species might go extinct and hence the prey species have developed certain defence mechanisms to reduce the impact of predation.

The prey of herbivores are plants. Unlike animals, plants cannot run away from their predators. Hence, plants have developed a remarkable variety of morphological and chemical defences against herbivores.

Some of them include:

• Thorns: These are hard, woody pointed structures that offer protection from the grazing animals. Examples of plants producing thorns are Acacia and Bougainvillea.
• Chemicals: Plants produce alkaloids such as nicotine, caffeine and quinine as defences against grazers and browsers. Calotropis produces very toxic cardiac glycosides that affect the heart. Hence, this plant is avoided by grazing cattle and goats.