Explain the structure of megasporangium.

Explanation

Structure of Megasporangium
The ovule is a small structure attached to the placenta by means of a stalk called Funicle.
The body of the ovule fuses with funicle in the region called hilum.
The ovule has one or two protective envelopes called integuments. These coves the ovule except at the tip where a small opening called micropyle.
The chalaza is present opposite to the micropylar end representing the basal pari of the ovule.
The integuments enclose a mass of cells with reserved food called nucellus.
Nucellus encloses the embryosac or female gametophyte.