Sex Determination - Research Article from Macmillan Science Library: Genetics

This encyclopedia article consists of approximately 7 pages of information about Sex Determination.
This section contains 1,970 words
(approx. 7 pages at 300 words per page)
Buy the Sex Determination Encyclopedia Article

Mammalian Mechanisms

Primary Sex Determination.

Early in an embryo's development (four weeks after fertilization, in humans), two groups of cells become organized into the gonad rudiment that will eventually develop into either the ovaries or testicles. These gonads will eventually be the source of gametes in the adult. However, at this early stage they are unstructured organs that lack sex-specific features but have the potential to develop into gonads.

The first visible indication of sex-specific development, occurring in week seven in humans, is in males, with the gonads restructuring into two distinct compartments: the testicular cords and the interstitial region. In females, the gonads appear to lack distinct structures until later in development. Primary sex determination, including the differentiation of an embryo's gonads, is dependent on genetic factors associated with the embryo's sex chromosomes.

Secondary Sex Determination.

Secondary sex determination involves the development of additional sex-specific characteristics, such...

(read more)

This section contains 1,970 words
(approx. 7 pages at 300 words per page)
Buy the Sex Determination Encyclopedia Article
Copyrights
Macmillan Science Library: Genetics
Sex Determination from Macmillan Science Library: Genetics. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
Follow Us on Facebook