Explain the structure of megasporangium.

Explanation

Structure of megasporangium :
Detailed Answer: Megasporangium is also called as ovule. The ovule is a small structure attached to the placenta by means of stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Each ovule has one/two protective envelopes called integuments. Integuments encircle the ovule except at the tip where a small opening called the micropyle is organised.
Opposite the micropylar end, is the chalaza, representing the basal part of the ovule. Enclosed within the integuments is a mass of cells called the nucellus. Cells of the nucellus have abundant reserve food materials. Located in the nucellus is embryo sac/female gametophyte. As ovule generally has a single embryo sac formed from a megaspore through meiosis.