cell division Flashcards
when does the cell cycle start
when a cell has been produced by cell division
what happens in G1
the cell grows and doubles its organelles
what happens at the g1 checkpoint
cell checks that the chemicals needed for replication are present and for any damage to DNA
what happens at the s phase
cell replicates DNA and is ready to divide by mitosis
what happens at G2 checkpoint
replicated DNA is checked for any mutations and if there isnt any it will start mitosis
what happens in the M phase
mitosis and cytokinesis
what 2 reasons do cells need to divide
repairing damaged tissues
asexual reproduction
why does interphase happen before mitosis
to allow cells to replicate their DNA ready for division
what happens during interphase
cells dna is replicated, organelles replicated
in prophase what condenses
chromosomes - making them shorter and fatter
what starts to move to opposite ends
centrioles
what do centrioles form
spindle fibres
what happens to the nuclear envelope during mitosis
it breaks down
what happens at metaphase
chromosomes line up along the middle of the cell
what do the chromosomes become attached to at metaphase
spindles
what happens at M1 checkpoint
cell checks chromosomes are attached to the spindle
what happens during anaphase
centrioles divide
what gets separated during anaphase
sister chromatids
what happens to the spindle during the anaphase
they contract pulling the cell apart
what happens during telophase
chromatids reach opposite poles and become chromosomes again
what happens to the nucleus in telophase
it divides into 2 nuclei
what happens in cytokinesis
cytoplasm divides forming two genetically identical cells