Types of Pollination by Pollen Source — NEET

Correct answer: B — S2 and S5 only

This question tests the understanding of megasporogenesis and female gametophyte development, including common misconceptions. Let's evaluate each statement: S1: Correct. NCERT states, 'The MMC undergoes meiotic division... Meiosis results in the production of four megaspores.' MMC is diploid, and meiosis produces haploid cells. S2: Incorrect. NCERT states, 'In a majority of flowering plants, one of the megaspores is functional while the other three degenerate.' Thus, not all four megaspores are functional in all angiosperms. S3: Correct. NCERT explains, 'This method of embryo sac formation from a single megaspore is termed monosporic development.' S4: Correct. NCERT states, 'Only the functional megaspore develops into the female gametophyte (embryo sac).' While NCERT Figure 1.8a shows the functional megaspore at the chalazal end, this is a general representation for the majority. The functional megaspore's nucleus then undergoes mitotic divisions. S5: Incorrect. NCERT states, 'Cells of the nucellus have abundant reserve food materials.' The stigma serves as the landing platform for pollen grains, not the nucellus. Therefore, statements S2 and S5 are NOT correct.