Question

Polyploid endosperm can be traced in

• A. Gnetum
• B. Welwitschia
• C. Ephedra
• D. All of the above

Answer 1

The correct option is A Gnetum

Gnetum, Welwitschia and Ephedra are gymnosperms. In gymnosperms, endosperm is haploid as it is formed before fertilisation but Gnetum is the only gymnosperm that shows double fertilisation (like angiosperms) in which, after the release of two male gametes in the embryo sac by the pollen tube, one of the male gametes fuse with the egg cell giving rise to zygote and the other male gamete fuses with the diploid secondary nucleus giving rise to a triploid primary endosperm nucleus or PEN. PEN then forms a triploid endosperm.

Hence Gnetum has triploid endosperm while Welwitschia and Ephedra have haploid endosperm.

So, the correct answer is 'Gnetum'.