Page 47 - Demo 1

The G2 phase extends from the compleon of DNA replicaon to the onset of
mitosis. At this stage, preparaon for cell division connues with the condensaon
of chromosomes and synthesis of microtubules.

Figure 26
Source: https://image.slidesharecdn.com/ssmitosiscellcyclecancerchs1920-160224182310/95/ss-human-biology-cell-
cycle-chs-19-and-20-10-638.jpg?cb=1456340052

Mitosis or M phase is the period when chromosomes divide. When a
cell reaches the end of G2, it enters mitosis – the second part of the cell cycle.
Cell division takes place in the M (mitosis) phase. During this phase, the
doubled nuclear contents of the parent cell are equally distributed to the
daughter cells. As a result of mitosis, the nuclei of the two daughter cells are
genecally idencal to the parent cell and to each other (that is, they all have the
same number and kinds of chromosomes). Thus, if the parent nucleus has six
chromosomes, each daughter nucleus also has six chromosomes of exactly the
same type.

Mitosis is a connuous process subdivided into four stages: prophase,
metaphase, anaphase, and telophase. At the beginning of the prophase,
chromosomes appear as long thin intertwined threads but, as this stage
connues, the chromosomes become shorter and thicker. In human cells, 46
chromosomes are present. Each replicated chromosome has two strands of

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