4. With a neat, labeled diagram, describe the parts of a typical angiosperm ovule.

An ovule is a female megasporangium where the formation of megaspores takes place.

The various parts of an ovule are –

$⇒$ Funiculus – It is a stalk-like structure that represents the point of attachment of the ovule to the placenta of the ovary.
$⇒$ Hilum – It is the point where the body of the ovule is attached to the funiculus.
$⇒$ Integuments –They are the outer layers surrounding the ovule that provide protection to the developing embryo.
$⇒$ Micropyle – It is a narrow pore formed by the projection of integuments. It marks the point where the pollen tube enters the ovule at the time of fertilization.
$⇒$ Nucellus – It is a mass of the parenchymatous tissue surrounded by the integuments from the outside. The nucellus provides nutrition to the developing embryo. The embryo sac is located inside the nucellus.
$⇒$ Chalazal – It is the based swollen part of the nucellus from where the integuments originate.