The
process of mitosis is complex and highly regulated. The sequence of
events is divided into phases, corresponding to the completion of one
set of activities and the start of the next. These stages are prophase,
prometaphase, metaphase, anaphase and telophase. During the process of
mitosis the pairs of chromosomes condense and attach to fibers that pull
the sister chromatidsto opposite sides of the cell. The cell then
divides in cytokinesis, to produce two identical daughter cells.
Because cytokinesis usually occurs in conjunction with mitosis, "mitosis" is often used interchangeably with "M phase".
However, there are many cells where mitosis and cytokinesis occur
separately, forming single cells with multiple nuclei in a process
called endoreplication. This occurs most notably among the fungi and
slime moulds, but is found in various groups. Even in animals,
cytokinesis and mitosis may occur independently, for instance during
certain stages of fruit fly embryonic development.[6] Errors in mitosis
can either kill a cell through apoptosis or cause mutations that may
lead to cancer.
No comments:
Post a Comment