ovum
Introduction
In higher animals the ovum differs from the sperm in that it is larger and is nonmotile, a smooth sphere or oval lacking the flagellum of the sperm. Like that of the sperm, its nucleus contains the chromosomes, which bear the hereditary material of the parent. A gamete, ovum or sperm, contains half the number of chromosomes found in the body cells of the parent, i.e., the gamete is haploid. In animals, ova contain stored food called the yolk, the amount of which varies in different species, depending on the length of time required for the embryo to become self-sufficient in obtaining nourishment outside the egg.
The term
Sections in this article:
- Introduction
- Plant Ova
- Fertilization and Maturation
- Oogenesis
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Cell Biology