The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Germ cells are one of two fundamental cell types in the human body. Germ cells are responsible for the production of sex cells or gametes (in humans, ovum and spermatozoa). Germ cells also constitute a cell line through which genes are passed from generation to generation.
The vast majority of cells in the body are somatic cells. Indeed, the term somatic cell encompasses all of the differentiated cell types, (e.g., vascular, muscular, cardiac, etc.) In addition, somatic cells may also contain undifferentiated stem cells (cells that, with regard to differentiation are still multipotential). Regardless, while the mechanism of genetic replication and cell division is via mitosis in somatic cells, in germ cells a series of meiotic divisions during gametogenesis produces male and female gametes (i.e., ovum and spermatozoa that upon fusion (fertilization) are capable of creating a new organism (i.e., a single celled zygote).
While somatic cell divisions via mitosis maintain a diploid chromosomal content in the daughter cells produced, germ cells--in contrast-- through a series of mitotic divisions produce haploid gametes (i.e., cells with one-half the normal chromosome compliment s--one autosomal chromosome from each homologous pair and a sex chromosome (X in females, X or Y).
Although all humans start out as single cell zygotes, the germ cells for each individual are set-aside early in embryogenesis (development). If the cells comprising the germ cell line are subject to mutation or other impairments, those mutations may be passed down to offspring. It is from the germ cell line that all spermatogonia and all oogonia are derived.