Zusammenfassung der Ressource
Mitosis & Meiosis
- Chromosomes
- Consist of DNA
wrapped around a
complex protein
scaffold
- Eukaryotic chromosomes
are made of chromatin which
is a complex of DNA and
proteins
- Dynamic pieces of
chromatin that can
alternate between tight
and loose compaction.
Highly compacted during
cell division
- Consist of 2 genetically
identical sister
chromatids after
S-phase
- Mitosis involves separation of identical sister chromatids
- Only germ-line cells undergo meiosis
- Meiosis I
- Prophase I
- Chromosomes
begin to condense
- Homologous chromosomes
form pairs. Each pair is called
a bivalent or tetrad.
- Crossing over
between homologous
chromosomes occurs
- After crossing over, the
sister chromatids are no
longer genetically
identical
- Metaphase I
- Paired
chromosomes align
on the equatorial
plane in the cell
- Anaphase I
- Homologous
chromosomes
separate and move
to opposite sides
- Telophase I
- Chromosome
movement is
completed and
new nuclei
begin to form
- Meiosis II
- Prophase II
- Chromosomes
condense and
become
attached to
spindle fibres
- Metaphase II
- Chromosomes
align on the
equatorial plane in
each cell
- Anaphase II
- Sister chromatids
disjoin and move
to opposite poles
in each cell
- Telophase II
- Chromosomes
condense and
nuclei form
- Cytokinesis
- The haploid daughter cells are
separated by cytoplasmic
membranes