Mitosis

From ZuluNotes - Free Leaving Cert Notes

Mitosis is the process by which a cell duplicates its genetic information (DNA), in order to generate two, identical, daughter cells. It is divided into 4 stages, Prophase, Metaphase, Anaphase and Telophase. Most cells divide by mitosis, these cells are called somatic cells and are generally involved in growth. The other cells, germ cells(eg. sperm) divide by meiosis and are involved in reproduction and gamete formation.

Contents 1 Preperation 2 Prophase 3 Metaphase 4 Anaphase 5 Telophase

Preperation

1. The chromatin replicates itself
2. The cell builds up a large store of energy
3. Organelles either replicate or are made

Prophase

• First the chromatin condense to form chromosomes.
• They then double to form sister chromatids
• The membrane disappears and the centrioles seperate and grow spindle fibres

Metaphase

• The centrioles move to the poles and attatch to the spindle fibres to the centromere, which is the point where the sister chromatids are joined together.

Anaphase

• The centromere splits
• The chromatids seperate and are drawn to opposing poles

Telophase

• The centriole duplicates
• The nuclear membran reforms
• The spindle breaksdown
• The cytoplasm divides in two
  • In plant cells a cell plate grows in the middle, and a cell wall is produced on either side.

There are now two daughter cells, both of which are identicle to the original parent cell.

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