Answer: The free-living, independent gametophyte.
- A The sporophyte plant generation in the life cycle
- B The free-living, independent gametophyte
- C The spore-producing structure within the sporophyte
- D A modified root adapted for a specific function
Correct answer: B. The free-living, independent gametophyte
Explanation: The prothallus is the free-living, independent, photosynthetic gametophyte of pteridophytes. It is small, flat, heart-shaped, and bears the sex organs (antheridia and archegonia). It represents the haploid (n) phase.
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.