Answer: Male gametophytes (pollen grains containing the male gametes).
- A Female gametophytes housed within the megasporangium
- B Male gametophytes (pollen grains containing the male gametes)
- C Sporophytes directly, bypassing the gametophyte generation
- D Embryos formed without any intervening fertilization step
Correct answer: B. Male gametophytes (pollen grains containing the male gametes)
Explanation: Heterospory: two types of spores. Microspores (small) → male gametophyte (pollen grain). Megaspores (large) → female gametophyte (embryo sac). Evolved in seed plants.
Double fertilisation in angiosperms: one male gamete fuses with the egg to form the diploid zygote (syngamy), while the second fuses with the two polar nuclei to form the triploid primary endosperm nucleus (triple fusion). Image: Triploid, CC BY 3.0, via Wikimedia Commons.
Concept context
Flower structure, pollination, double fertilization, and seed/fruit development - the highest-scoring Class 12 biology chapter in NEET.
Read the full Sexual Reproduction in Flowering Plants notes →