Chromosomes - Research Article from Macmillan Science Library: Plant Sciences

This encyclopedia article consists of approximately 4 pages of information about Chromosomes.
This section contains 1,181 words
(approx. 4 pages at 300 words per page)
Buy the Chromosomes Encyclopedia Article

Physical Description

DNA does not exist in the cell as an isolated chemical, but rather as an elaborately packaged and microscopically visible structure called a chromosome. All chromosomes are comprised of both DNA and proteins, although only the DNA contains the genetic code. Each chromosome carries thousands of genes, and each time a cell divides all of the cell's chromosomes are replicated, divided, and sorted into two pools, one for each new daughter cell. Each chromosome has a centromere (the site on the chromosome where the spindle attaches), which functions as a "luggage handle" for the genetic cargo. This attachment provides the mechanical basis for movement of chromosomes toward one of the two pointed ends (poles) of the football-shaped spindle apparatus.

The anaphase stage of mitosis in the cell of an allium root. The chromosomes, replicated and condensed into chromatids, are lined up along an axis. The anaphase stage of mitosis in the cell of an allium root. The chromosomes, replicated and condensed into chromatids, are lined up along an axis.

The entire complement...


(read more)

This section contains 1,181 words
(approx. 4 pages at 300 words per page)
Buy the Chromosomes Encyclopedia Article
Copyrights
Macmillan Science Library: Plant Sciences
Chromosomes from Macmillan Science Library: Plant Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
Follow Us on Facebook