Tuesday, January 21, 2014

Day 26: The Cell Cycle

The Cell Cycle has five stages.

The first stage is interphase in the G2 phase it is when the nucleus is really dark. DNA replication occurs in this phase using the enzymes previously talked about which is Helicase, RNA primer, DNA poly III, and DNA poly I.

After interphase the next stage is prophase, prophase is when the first sign of division is indicated. This part is a little more obvious the chromatin has been condensed into lots of chromosomes. Each chromosome is composed of two chromatids joined at the centromere. The chromatids will thicken and shorten and the it will attach to forming spindles. The spindles are made of microtubules. The microtubules will move to poles kinda of like magnetic poles.

Metaphase is the third stage and all the chromosomes move to the center and line up.

Anaphase is when the centromeres divide and sister chromatids move to opposite ends.

Telophase is when the spindle fibers disappear and the nucleus begins to reform and the chromosomes de-condense.

Cytokinesis is the final stage and is when the cells divide completely and have their own membranes. The result is 2 daughter cells that have identical genetic information to the parent cells.

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