Mitosis Flashcards
When does the cell cycle begin?
When a cell has been produced by cell division
How does the cell cycle end?
When the cell dividing produces two indentical cells
What are the two stages of the cell cycle?
Cell growth
Cell division
What is the stage of cell growth called?
Interphase
What are the three separate stages within interphase?
G1
S
G2
What happens in the G1 stage of interphase?
Cell grows and new organelles are made
What happens in the S stage of interphase?
DNA replicates itself to make it ready for mitosis
What happens in the G2 stage of interphase?
The cell keeps growing and proteins needed for cell division are made
Which part of the cycle does the cell spend most of its time in?
Interphase
Briefly, what happens during mitosis?
A parent cell divides to produce two genetically identical daughter cells
What is mitosis needed for?
Growth of multicellular organisms and repairing damaged tissues
What are the 4 stages of mitosis?
Prophase
Metaphase
Anaphase
Telephase
When mitosis begins, what are the chromosomes joined up in the middle by?
Centromere
What are two strands of the same chromosome called?
Sister chromatids
What happens in prophase?
1) chromosomes condense
2) centrioles move to polar edges of the cell
3) spindle fibres form
4) nuclear envelope breaks down
What happens in metaphase?
1) chromosomes line up in the middle
2) spindle fibres attach to the centromeres
What happens in anaphase?
1) the centromeres divide
2) spindle fibres pull the chromosomes apart to separate ends of the cell
3) the chromatids make a V shape
What happens in telophase?
1) the chromatids reach opposite ends of the cell
2) nuclear envelope forms around the groups of chromosomes to form two nuclei
What is cytokinesis?
The cytoplasm dividing
What is cancer?
Tumour that invades surrounding tissue
How is a tumour formed?
When a cell divides uncontrollably
Give an example of a drug which prevents the synthesis of enzymes needed for DNA replication.
Chemotherapy
How is radiation used as a treatment for cancer?
they damage DNA
at certain parts in the cycle its checked for damage
if damage is found, the cell kills itself
