Lecture 10 - The Cell Cycle Flashcards
What are the 2 main phase of the cell cycle?
I phase (interphase) M phase (mitosis + cytokinesis)
What are the 3 parts of interphase?
G1 (G0), S, and G2
What is generation time?
The length of time it takes the population to double (one cell into two cells)
How do you figure out the time of each phase? (mitotic index)
Fraction number of cells in the particular phase multiplied by the generation time
In a 24 hour cell cycle, how long does each phase take?
S phase - 6-8 hours
M phase - 30-45 min
G2 - 4-6 hours
G1 - 8-10 hours
If the cell cycle takes longer than 24 hours, say a week or month, what phase changes and why only that one?
G1 changes, this is due to the fact that all the other processes are ‘set in stone’ and don’t need addition time for their phase to be carried out
What are the 2 tasks that cells can undergo in G1?
Remain in G1 or decide to divide (move into S)
What is terminal differentiation?
Cells exit the cell cycle and can no longer divide, move into the G0 phase
There is no coming back from this, cells go here once their limit of division has been reached
What are the 5 stages of mitosis?
Prophase, Prometaphase, Metaphase, Anaphase, Telophase/cytokinesis
What happens in prophase?
Chromosomes appear
Centrosomes separate as mitotic spindle forming
Nucleoli disappear
What happens in prometaphase?
Nuclear envelope breaks apart
Spindle microtubules attach to chromatids
What happens in metaphase?
Alignment at metaphase plate
What happens in anaphase?
Separation of sister chromatids
What happens in telophase/cytokinesis?
Chromosomes begin to uncoil
Nuclear envelope reforms
Cell divides into two
What is the flow of cytometry?
A mixture of cells is treated with fluorescent antibodies or a DNA dye
Cells flow single file
Fluorescent light intensity is measured
Scattered light is used to measure cell shape and size
