6.2 Mitosis
First review @November 8, 2023
Practise Q's Done
The importance of mitosis
mitosis is the process of nuclear division within eukaryotic cells
mitosis produces two genetically identical daughter cells, except when there are
mutations
mitosis is used for cell repair, replacement and growth in multicellular organisms such as
plants, animals and fungi. it is also used for asexual reproduction within unicellular
organisms such as the Amoeba species and and also prokaryotic cells— however
prokaryotic cells use a slightly different process called binary fission
Chromosomes
before mitosis can occur, the DNA is replicated during interphase
each DNA molecule (chromosome) is duplicated into two identical DNA molecules
called chromatids
the two chromatids join at the centromere— it is important to keep the chromatids
together so they can be strategically moved
The stages of mitosis
four stages: prophase, metaphase, anaphase and telophase
prophase
6.2 Mitosis 1
, chromatin fibres (complex made form various proteins, DNA and RNA) coil and
condense— chromosomes become more visible under light microscope
nucleolus begins disappears and nuclear membrane begins to break down
protein microtubules from spindle- shaped structures linking the poles of the cell—
this is necessary to move the chromosomes into the correct positions
in animal cells and some plant cells two centrioles migrate to the poles of the cell to
aid the formation of the spindle
spindle fibres attach to centromeres and begin to move chromosomes to centre of the
cell
by the end of prophase the nuclear membrane would have disappeared
metaphase
spindle fibres move chromosomes by the centromeres to the middle of the cell to
form the metaphase plane— the chromosomes are then held in position
6.2 Mitosis 2
First review @November 8, 2023
Practise Q's Done
The importance of mitosis
mitosis is the process of nuclear division within eukaryotic cells
mitosis produces two genetically identical daughter cells, except when there are
mutations
mitosis is used for cell repair, replacement and growth in multicellular organisms such as
plants, animals and fungi. it is also used for asexual reproduction within unicellular
organisms such as the Amoeba species and and also prokaryotic cells— however
prokaryotic cells use a slightly different process called binary fission
Chromosomes
before mitosis can occur, the DNA is replicated during interphase
each DNA molecule (chromosome) is duplicated into two identical DNA molecules
called chromatids
the two chromatids join at the centromere— it is important to keep the chromatids
together so they can be strategically moved
The stages of mitosis
four stages: prophase, metaphase, anaphase and telophase
prophase
6.2 Mitosis 1
, chromatin fibres (complex made form various proteins, DNA and RNA) coil and
condense— chromosomes become more visible under light microscope
nucleolus begins disappears and nuclear membrane begins to break down
protein microtubules from spindle- shaped structures linking the poles of the cell—
this is necessary to move the chromosomes into the correct positions
in animal cells and some plant cells two centrioles migrate to the poles of the cell to
aid the formation of the spindle
spindle fibres attach to centromeres and begin to move chromosomes to centre of the
cell
by the end of prophase the nuclear membrane would have disappeared
metaphase
spindle fibres move chromosomes by the centromeres to the middle of the cell to
form the metaphase plane— the chromosomes are then held in position
6.2 Mitosis 2
