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Mitosis
and Meiosis
Mitosis
and meiosis are processes of cell division.
Mitosis creates cells that have the same genetic information. Meiosis consists of two processes, which
create cells that are genetically different from each other.
The stages of mitosis are:
Interphase:
-The cell makes a copy of its DNA and centrosomes
Prophase: -The DNA is compacted into chromosomes
-Each copy of DNA is called a sister chromatid, which is held together
by a
centromere. These chromatids make up a chromosome.
Prometaphase: -The nuclear envelope breaks down
Metaphase:
-Chromosomes align on the equatorial plate (the cells midline).
Anaphase:
-The centromere pairs separate, and the daughter chromosomes move
toward
the poles.
Telephase:
-The nucleus re-forms and the cell divides in two.
The first
process of meiosis is similar to mitosis, but twice as many chromosomes are
created. The two processes of meiosis are
meiosis I and meiosis II.
Meiosis
I:
Prophase I:
-The chromatin condense
-Recombination happens when the two strands of DNA splits and pair
with
each other
-Genetic material is exchanged and the nuclear envelope breaks down.
Metaphase I: -Pairs of sister chromatids line up on the
equatorial plate.
-The amount of paired chromosomes is twice the amount of chromosomes
that occurs during
metaphase in mitosis.
Anaphase I:
-The sister chromatids move to opposite poles of the cell.
Telophase I: -The chromosomes gather into nuclei, and the
original cell divides.
Meiosis
II:
Prophase II: -The chromosomes condense again, but the DNA
does not make another
copy of itself.
Metaphase II: -Chromosomes line up at the equatorial plate.
Anaphase II: -The centromeres divide and sister chromatids
migrate separately to each
pole.
Telophase II: -The chromosomes gather into nuclei and the
cells divide into four haploid
daughter cells.
Home Mitosis Meiosis
P53 Apoptosis Cancer History of Cancer
Treatments Transgenic Mice
Dox Treatment Future of Dox Credits