Concept
Statements |
Emphasis
in
your teaching
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General
importance
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1.All
cells are derived from preexisting cells by the process
of cell division. Cells die either because they are damaged
(necrosis)
or by the active process of programmed cells death (apoptosis). |
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2.During
typical cell division, the two daughter cells can receive
the same number of chromosomes as were present in the
mother cells (mitosis)
or half the number of chromosomes (meiosis). |
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3.In
eukaryotic cells, the processes of chromosome
segregation (mitosis and meiosis) are
mediated by a macromolecular machine, the spindle.
The spindle is composed of microtubules,
microtubule-associated and chromosome-associated proteins. |
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4.In
eukaryotic cells, the processes of cell division (cytokinesis)
is mediated by a macromolecular machine, the cleavage
furrow in animal cells and the phragmoplast in
plants. In prokaryotes, the formation of a septum divides
cells. |
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5.
In multicellular eukaryotes, cells can be part of the
body (somatic cells)
or the germ line.
Most somatic cell can divide only a limited number of
times before they senesce. The exception of stem
cells, which can divide in an unlimited
manner. |
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6.
Stem cells divide asymmetrically, one daughter remains
a stem cell and the other goes on to differentiate. |
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7.
Cellular differentiation is associated with changes in
gene expression, that is which genes are transcribed
and which gene products (RNAs and polypeptides) accumulate
and are active. |
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8.
Cellular differentiation is often associated with changes
in the organization of the chromatin,
so that these changes may be effectively irreversible. |
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9.
To survive and differentiate correctly, cells depend
upon external signals. Generally these include secrete
factors made by neighboring cells. |
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10.
In the absence of the appropriate external signals, a
normal cell will undergo programmed
cell death (apoptosis). |
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11.
While the death of a damaged (necrotic) cell leads to inflammation,
apoptotic cell death does not, and the cell corpse is
rapidly engulfed by neighboring cells. |
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12. S phase (DNA replication) and M phase (mitosis) are
temporally distinct stages of the cell cycle. |
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