For the protection from herbivore animals, the plant Calotropis secretes the highly poisonous compound known as -
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Cardiac glycosides
Option (1) Cardiac nucleotides — Incorrect. Nucleotides are the building units of DNA and RNA. They are present in every cell and are not a poison.
Option (2) Cardiac glycoproteins — Incorrect. Glycoproteins are proteins with sugar chains attached, found on cell surfaces. They are not the defence chemical of Calotropis.
Option (3) Cardiac glycosides — Correct. Calotropis makes highly poisonous cardiac glycosides, which act on the heart. That is why cattle and goats do not graze on this weed.
Option (4) Cardiac globulins — Incorrect. Globulins are a group of proteins, such as those in blood plasma. They are not the poison of Calotropis.
NCERT Extract:
Population Interactions – “… 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.”