Zusammenfassung der Ressource
Cells cycle
- G1-new proteins and organelles formed
- S phase- DNA replicated and chromatin doubles
- G2- RNA and proteins sysnthesised
- MITOSIS
- Prophase
- nucleolus breaks down,
nucleus breaks down,
chromatids condense,
centrioles migrate to
opposite poles
- Metaphase
- spindle fibres form,
chromosomes line
up at the equator,
microtubles of
spindle attach to
centromeres
- Anaphase
- centromeres divide,
spindle fibres move
chromatids to
opposite poles
- Telophase
- chromosomes reach
opposite poles,
nuclear envelope
forms around each
- Cytokinesis
- Animal cell:
cleavage furrow
forms, furrow
deepens and when
membrane fuses,
cell is cleaved in 2
- Plant cell: golgi
bodies produce
vesicles that
collect and form
an equatorial
cell plate
- MEIOSIS
- Prophase I
- chromosomes condense
(evident homologous are
paired-bivalent). coromatids
appear, chromatids break
at chiasmata and rjoin with
another chromatid
CROSSING OVER
- Metaphase I
- bivalents move to equator
randomly, chromosome
pairs attach to spindle fibres
by centromere
INDEPENDENT
ASSORTMENT
- Anaphase I
- chromosomes
move
towards
poles
- Telophase I
- chromosomes
reach poles, nuclear
membrane forms (
nucleus has haploid
chromosomes)
- Prophase II
- New spindle
fibres form at
right angles to
old
- Metaphase II
- chromosomes
line up along
equator
- Anaphase II
- chromatids split
at centromere
and pull to
opposite poles
- Telophase II
- nuclear
envelope
forms