Structure & Types of ovule

The ovule is a multicellular oval-shaped structure which originates from the placenta and lies inside the chamber of the ovary. Gymnosperms – Naked Angiosperms – Integumented A fully mature ovule consists of the stalk or funicle and the body. The body of the ovule shows two ends – Basal end - Chalaza & Upper end - Micropylar end Hilum - The point of attachment of the funicle with the body Body of the ovule Integuments Nucellus & Embryo Sac Integuments Protecting layers Unitegmic or bitegmic Micropyle-small opening at the apex of the integument, Entrance for Pollen tube. Nucellus Parenchymatous, nourishing Embryo sac/female gametophyte - oval, at the micropylar end; contains egg apparatus. Egg Apparatus Egg cell or ovum – Central, forms the female gamete Synergids - nonfunctional, short-lived Antipodal cells – 3, non functional, short-lived Nucleus – 2, Polar nuclei, one fuses with male gamete and grows into the endosperm of the seed. Types of Ovule Orthotropous Anatropous Hemianotropous Campylotropous Amphitropous Circinotropous Dr. T. Annie Sheron Annie Sheron Kakatiya Government College