Write briefly about the different types of ovules.

Explanation

The ovule is a megasporangium with one or two integuments. In Angiosperms three main types of ovules are present. They are :
1) Orthotropous ovule : it is straight ovule with micropyle, chalaza and funiculus arranged in one stratght line. lt is a primitive type of oyule,
Ex : Polygonum, Piperaceae.

2) Anatropous ovule : It is a inverted type of ovule. Due to unilateral growth of funicle, the whole body of the ovule is inverted through `180^(circ)`. As a result the micropyle comes close to the base of the funicle. The most common type of ovule found in several families.
Ex : Helianthus, Tridax.

3) Gampylotropous ovule : In this type of body of the ovule is bent more or less at right angles to the funicle. The microphyle part of the ovule become curved, without any curvature in the embryosac.
Ex : Fabaceae, Brasicaceae.