With a neat labelled diagram, describe the parts of a typical angiosperm ovule.
The ovule is an integumented megasporangium within which the meiosis and megaspore formation takes place. It is attached to the placenta by means of a stalk called funicle. It develops into a seed after fertilisation. The junction between an ovule and funicle is called hilum, which later becomes a
scar on the seed. Each ovule has one or two protective envelopes called integuments, which encircle the ovule except at a tip where a small opening called micropyle is located. The basal part of an ovule just opposite to micropyle is called chalaza. Enclosed within the integuments is a mass of
cells called nucellus. Cells of the nucellus are rich in reserve food materials. An ovule generally has a single embryo sac or female gametophyte developed from a megaspore through reductional division and located within the nucellus.