Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their
- Nutritive value
- Growth response
- Effect on reproduction
- Defence action
Answer
(4) Defence action
Solution
As per NCERT, plants have evolved chemical defences against herbivores (grazers and browsers): they produce and store chemicals such as nicotine, caffeine, quinine, strychnine and opium.
These chemicals make the herbivores sick, inhibit feeding or digestion, disrupt reproduction or even kill them.
∴ They are produced for defence action.
Answer: (4)