Explain the structure of megasporangium.

Explanation

The angiosperm ovule is called Megasporangium. It is attached to the placenta by funcile and the body of the ovule fuses with funicle at Hilum. It has one or two protective envelopes called integuments. Integuments posses a small opening at the tip called micropyle. Opposite to micropylar end, is the chalaza, representing base of the megasporangium.

Enclosed within the integuments is a mass of cells with abundant food reserve materials called the nucellus. Located in the nucellus is the embryo sac or female gametophyte.