Question

The central cell of the mature embryo sac contains two polar nuclei. What is the ploidy level of the central cell after the two polar nuclei fuse?

Options

• Triploid (3n)

• Diploid (2n)

• Haploid (n)

• Tetraploid (4n)

Answer 1

The central cell contains two polar nuclei, each haploid (n). When these two polar nuclei fuse, they form a diploid (2n) secondary nucleus. This secondary nucleus later participates in triple fusion with a male gamete to form the triploid (3n) endosperm nucleus.