cell division (mitosis) Flashcards
what does mitosis produce?
2 genetically identical daughter cells
why is mitosis necessary?
for the growth of multicellular organisms, and repairing damaged tissues
what are the stages of the cell cycle?
mitosis
gap phase 1
synthesis
gap phase 2
what happens in gap phase 1?
cell grows and new organelles/proteins are made
what happens in synthesis?
cell replicates its DNA, so it is ready to divide by mitosis
what happens in gap phase 2?
cell keeps growing, proteins needed for cell division are made
what happens in interphase?
the cell carries normal functions
DNA unravelled and replicated
organelles are replicated
ATP content increased
what happens in prophase?
chromosomes condense get shorter and fatter centrioles move to opposite ends of the cell forming spindle fibres nuclear envelope breaks down chromosomes lie free in the cytoplasm
what happens in metaphase?
chromosomes line up along the middle of the cell
are attached to the spindle by their centromere
what happens in anaphase?
centromeres divide
sister chromatids are separated
spindle fibres contract
chromatids are pulled to opposite poles of the cell
what happens in telophase?
chromatids reach opposite poles
uncoil- become long and thin
nuclear envelope forms around chromosomes to make two nuclei
cytokinesis finishes
results in two genetically identical daughter cells
what is cancer?
uncontrolled cell growth which leads to tumour formation
how is cancer caused?
mutation in a gene involved in the cell cycle cell cycle no longer controlled apoptosis not completed uncontrolled cell growth tumour formation
what is a benign tumour?
doesn’t spread
what is a malignant tumour?
spreads
