Answer: Genetic variation and vigor (hybrid vigor).
- A Genetic uniformity across successive generations
- B Genetic variation and vigor (hybrid vigor)
- C Reproduction of the pollinating insect species itself
- D Dormancy mechanisms that delay seed germination
Correct answer: B. Genetic variation and vigor (hybrid vigor)
Explanation: Cross-pollination between different plants promotes genetic variation and often results in hybrid vigor (heterosis) -- more robust offspring.
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 →