Answer: Alternation between sporophyte (2n) and gametophyte (n) generations.
- A Cyclical seasonal changes in vegetative growth rate across the year
- B Alternation strictly between sexual reproduction in summer and asexual reproduction in winter
- C Alternation between sporophyte (2n) and gametophyte (n) generations
- D Diurnal growth cycles governed by stomatal opening and closing
Correct answer: C. Alternation between sporophyte (2n) and gametophyte (n) generations
Explanation: In alternation of generations, the diploid sporophyte (2n) produces haploid spores by meiosis, which grow into the haploid gametophyte (n) that produces gametes by mitosis. Fertilization restores 2n.
Plants evolved from water-dependent algae through increasingly land-adapted groups, gaining vascular tissue (Pteridophyta), then seeds (Gymnosperms), and finally fruit-enclosed seeds (Angiosperms) - each step reducing dependence on water for reproduction.
Concept context
Classification of plants from algae to angiosperms. Understanding plant diversity is essential for NEET.