Question

During the formation of embryo sac, the functional megaspore undergoes:

• A. Two mitotic divisions
• B. Two meiotic divisions
• C. Three meiotic divisions
• D. Three mitotic divisions

Answer 1

The correct option is D Three mitotic divisions

The megaspore mother cell undergoes meiosis to give rise to 4 haploid cells. Three haploid cells degenerate and one survives to become the embryo sac. The embryo sac enlarges in size and the haploid nucleus undergoes mitosis to form 2 haploid nuclei. The two haploid nuclei further undergo mitosis to form 4 haploid nuclei within the embryo sac. In the final round of mitosis 8 haploid nuclei are produced. Hence, the functional megaspore undergoes 3 mitotic divisions to form eight celled mature embryo sac.