Question

The process of double fertilization occurs:

a. only in angiosperms.
b. in all angiosperms and gymnosperms.
c. only in angiosperms and Ephedra.
d. only in angiosperms and Gnetum.
e. only in angiosperms, Ephedra, and Gnetum.

Answer 1

Double fertilization occurs only in angiosperms, where two sperm nuclei are delivered to the female gametophyte. One sperm fuses with the egg to form a zygote, while the other fuses with the central cell to form the endosperm.

Step-by-step explanation:

Double fertilization occurs only in angiosperms. In this process, the male gametophyte (pollen) delivers two sperm nuclei to the female gametophyte (embryo sac) inside the ovule. One sperm nucleus fuses with the egg to form a diploid zygote, while the other sperm nucleus fuses with the central cell to form a triploid endosperm. This unique reproductive process is an important characteristic of flowering plants.