Chapter 11 - Animal Reproduction

The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with other individuals in the environment to maintain themselves for a period of time sufficient to enable them to produce tissue nonessential to their own survival, but indispensable to the maintenance of the species. The additional tissue, reproductive tissue, usually becomes separated from the individual to form a new, independent organism.

Reproductive System

Oogenesis is the production of eggs, begins in the fetus. Oogonia, the diploid stem cells of female gametes, are converted to primary oocytes before birth. Each month, one primary oocyte completes meiosis I, producing a large secondary oocyte. Meiosis II of the secondary oocyte produces a functional ovum, but does not occur in humans unless a sperm penetrates the secondary oocyte. The ovarian cycle has Two phases: Follicular phase and Luteal phase

Lecture 26