Transcript Meiosis - Yourhomework

Meiosis
By Jessica Sheeder
Added to by Janet Baity
Meiosis
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Is a special type of cell division that
happens only in sex cells (reproductive
organs)
During meiosis the cell goes through
two cell divisions
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Meiosis 1
Meiosis 2
Meiosis 1
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There are the same Five steps that we
already learned in Mitosis
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1. Interphase (not part of meiosis or mitosis but
part of the cell cycle)
Prophase
Metaphase
Anaphase
Telophase
However, PAIRED chromosomes separate
Meiosis 1Interphase 1
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The cell continues to grow and
prepare for meiosis 1
DNA is being copied from the
parent cell
Meiosis 1Prophase 1

In Prophase 1:
 Chromosomes
condense
 Nuclear
membrane
breaks down
 Chromosomes
then pair up
Meiosis 1
Metaphase 1
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Chromosome pairs
line up
Chromosomes
arrange as pairs in
the middle of the
cell
Spindle fibers
attach to
centromeres of
each chromosome
Meiosis 1Anaphase 1
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Chromatid pairs
are torn apart
they DO NOT
SEPARATE
Single
chromosomes
move to opposite
sides of the cell
Meiosis 1
Telophase 1
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Cell divides
No more replication
of genetic material
 (no more copies of
DNA are made
before it divides
again)
Each has ½ the
normal number of
chromosomes
Meiosis 2
Prophase 2
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The cell prepares to
divide again
Each chromosome is
made up of two
copies (sister
chromatids)
This is exactly like
mitosis
Meiosis 2Metaphase 2
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Chromosomes line
up in the center of
the cell
Spindle fibers attach
to the centromeres
of the individual
chromosomes
Meiosis 2
Anaphase 2
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Chromosomes are
ripped apart
Once
chromosomes are
apart they move
to opposite sides
of the cell
Meiosis 2Telophase 2
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Cell membrane
appears and cells
divide
Cytokineses splits
the cytoplasm into
four new daughter
cells
Meiosis-big picture
When going through Meiosis
you start out with one cell and
end up with 4 new cells that are
identical
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