mitosis Flashcards
what is mitosis needed for
cell growth
repair
replace worn out cells
what does mitosis produce
two genetically identical daughter cells
what do all cells not have the ability to?
divide
cells that can divide have a…
cell cycle
mitosis is part of a
cell cycle
what are the phases of a cell cycle
G1
S
G2
Mitosis
what happens in G1
cell grows
new organelles + proteins made
what happens in S phase
cell replicates DNA
ready to divide by mitosis
what happens in G2 phase
cell keeps growing
proteins needed for cell division are made
what stage is before mitosis
interphase
what happens in interphase
cell carries out normal functions ; but is ready to divide
DNA is unravelled + replicated
organelles also repilcated
ATP content increases
mitosis is a … process
controlled
what are the 4 stages of mitosis
prophase
metaphase
anaphase
telophase
what happens in prophase (5)
chromosomes condense
shorter
thicker
centrioles form on either side of cell
spindle fibres formed
nuclear envelope disintegrates
chromosomes free in cytoplasmwhat happens in metaphase
chromosomes line up at equator
chromosomes attached to spindle fibre by centromere
what happens in anaphase
centromere divides ; separates sister chromatids
spindle fibres contract ; pulls away chromatids to either side
chromosomes appear v shaped
what happens in telophase
chromatids uncoil - long + thin again
nuclear envelope reforms
2 nuclei formed
what happens in cytokinesis
cytoplasm divides
two new genetically identical daughter cells
cancer is
uncontrolled cell division
mitosis is controlled by
genes
what causes a tumour
mutation in gene
leading to uncontrolled cell division
describe a way cancer treatments target cells
G1 phase targeted
proteins for DNA replication not synthesised
cell can’t go into s phase
cell kills itself
describe a way cancer treatments target cells
S phase targeted DNA damaged by radiation + drugs damage detected at checkpoint cell kills itself prevents tumour growth
