Choose the correct statement(s) I. Genetic variation can only arise from sexual reproduction.

Question

Choose the correct statement(s):

I. Genetic variation can only arise from sexual reproduction.

II. Organic variation is always beneficial for the survival of a species.

III. Environmental factors have no effect on organic variation.

IV. Some isolating mechanisms are pre-zygotic, meaning they occur before fertilization.

1. A. I and II are correct
2. B. I, II, III are correct
3. C. Only IV is correct (Correct answer)
4. D. All are correct

Correct Answer

Option C — Only IV is correct

Detailed Solution & Explanation

The correct answer is Only IV is correct.

Key Points

• Statement I is FALSE - mutations in asexual organisms also create genetic variation.
• Statement II is FALSE - variations can be harmful or neutral. Statement III is FALSE - environment affects phenotypic expression.
• Only IV is correct - pre-zygotic isolation (habitat, temporal, behavioral, mechanical, gametic) occurs before fertilization.