What is the small opening at the entrance of the ovule called?

The small opening at the entrance of the ovule is known as the micropyle. This structure plays a crucial role during fertilization in flowering plants (angiosperms). The micropyle is the point through which the pollen tube enters the ovule, allowing the sperm cells to fertilize the egg cell contained within. Its presence enables the efficient transfer of genetic material, leading to the formation of seeds.

In the context of plant anatomy, the other terms refer to different structures or stages. The fruit is a mature ovary that develops from fertilized ovules, serving as a protective environment for seeds and aiding in their dispersal. Cotyledons are the first leaves that appear on a plant embryo, providing initial nutrition during germination. The hypocotyl refers to the region of a developing seedling located between the cotyledons and the root, acting as a stem that supports the plant as it grows.

Thus, identifying the micropyle as the small opening at the entrance of the ovule emphasizes the importance of this structure in the reproductive process of plants.