From Seed to Seed:
Plant Science for K-8 Educators

 

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Types of Cell Division


Mitosis. Somatic cells undergo mitosis (my-TOE-sis; Gr. mitos = thread). Cell division through mitosis is how a plant forms new tissues and grows in size. Mitosis results in two daughter cells that are identical to the parent cell.

Cells undergoing mitosis pass through what is referred to as the cell cycle. The cell cycle is divided into four phases (G1, S, G2, M). The G1, S, and G2 phases are termed interphase. During interphase, replication takes place. Replication involves the doubling of the chromatin within the nucleus. Concurrent with this activity in the nucleus, the rest of the cell is preparing to divide into two daughter cells. This involves the duplication and synthesis of all other cellular components.

Mitosis (the M phase) is further divided into six phases:


1) During early prophase, the chromatin appear as long threads scattered throughout the nucleus.

2) In mid prophase, the chromatin becomes condensed into distinct chromosomes. Because of replication, each chromosome is composed of two genetically identical and parallel strands joined at their centers. These strands are called sister chromatids. The location at which the sister chromatids are joined is called the centromere.

3) In late prophase, the nuclear envelope begins to disintegrate.

4) The sister chromatids line up near the center of the cell in metaphase...

5) ...and pull apart from one another, toward opposite ends of the cell, in anaphase.

6) During telophase, mitosis is completed as a cell plate is formed and two identical daughter cells are produced. These daughter cells are diploid and are now effectively parent cells, ready to divide.

 

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