Sexual Reproduction

When male and female gametes are morphologically distinct, the condition is known as Heterogametes.

(A) Homogametes - Incorrect: This refers to morphologically similar gametes (isogametes).

(B) Heterogametes - Correct: Describes distinct gametes (sperm and egg in most animals).

(C) Hermaphrodites - Incorrect: Refers to organisms producing both gamete types, not their morphology.

(D) Sexual Dimorphism - Incorrect: Describes physical differences between sexes, not gametes.

The correct answer is (B) Heterogametes, exemplified by human sperm (small, motile) and egg (large, non-motile).