Download BLM 2-30, Compare the Events of Meiosis and Mitosis Key Meiosis I

BLM 2-30, Compare the Events of Meiosis and Mitosis Key
Meiosis I
Mitosis
Prophase I
Prophase (early and late)




nucleolus disappears
nuclear membrane disappears
spindle fibres form
homologous chromosomes pair up and each
attach
to spindle fibres
 non-sister chromatids exchange genetic material
(crossing over)




nucleolus disappears
nuclear membrane disappears
spindle fibres form
individual chromosomes attach to spindle fibres
Metaphase I
 homologous chromosomes pair up at the equator
Metaphase
 chromosomes form a single line at the equator
Anaphase I
 spindle fibres contract and shorten
 homologous chromosomes attached to
Anaphase
 spindle fibres contract and shorten
 the centromere pulls apart, and the sister
centromeres
separate and are pulled to opposite poles by the
spindle fibres
chromatids separate and are pulled to opposite
poles by the spindle fibres
Telophase I
 one chromosome from each homologous pair is
Telophase
 one complete set of chromosomes is now at each
at



each pole of the cell
the spindle fibres disappear
the nucleolus appears within each nucleus
the nuclear membrane forms



pole of the cell
the spindle fibres disappear
the nucleolus appears within each nucleus
the nuclear membrane forms
Interkinesis
 cell divides in two (not genetically identical to


parent cell)
cell will grow and make proteins like interphase in
mitosis
no replication of DNA in this stage
Cytokinesis
 cell divides in two (genetically identical to parent
cell)
 cell will grow and make proteins like interphase in

mitosis
DNA will replicate later in interphase




Meiosis II
Mitosis
Prophase II
Prophase (early and late)
nucleolus disappears
nuclear membrane disappears
spindle fibres form
individual chromosomes attach to spindle fibres




nucleolus disappears
nuclear membrane disappears
spindle fibres form
individual chromosomes attach to spindle fibres
Metaphase II
 X-shaped chromosomes form a single line at the
equator
Metaphase
 X-shaped chromosomes form a single line at the
equator
Anaphase II
 spindle fibres contract and shorten
 the centromere pulls apart and the sister
chromatids
separate and are pulled to opposite poles by the
spindle
Anaphase
 spindle fibres contract and shorten
 the centromere pulls apart, and the sister
chromatids separate and are pulled to opposite
poles by the spindle
Telophase II
Telophase
 half of a complete set of chromosomes is now at
 one complete set of chromosomes is now at each
each pole of the cell (one chromosome for each
pair)
 the spindle fibres disappear
 the nucleolus appears within each nucleus
 the nuclear membrane forms
 the spindle fibres disappear
 the nucleolus appears within each nucleus
 the nuclear membrane forms
pole of the cell
Cytokinesis
 cell divides in two (total four daughter cells not

genetically identical to parent)
cell will grow and make proteins like interphase in
mitosis
Cytokinesis
 cell divides in two (genetically identical to parent)
 cell will grow and make proteins like interphase in
mitosis