cell cycle

Question 1

what are the stages in a cell cycle?

Answer 1

mphase- pmat
interphase- 1.G1-G0 2.S phase 3.G2 phase

Question 2

what are the two checkpoints?

Answer 2

G1/S phase
G2/M phase

Question 3

what is the purpose of the checkpoints?

Answer 3

1.to prevent uncontrolled cell division
2. to detect repair and damage
3.to ensure the cell cycle cannot be reversed
4.DNA is duplicated only once during the cell cycle

Question 4

describe the M phase

Answer 4

this is the stage in which the cell goes through mitosis
cell growth stops
nuclear division (pro,meta,ana,telo phase)
cytokinesis

Question 5

what happens in the check point of the M phase?

Answer 5

triggers condensation of chromatin
meta phase checkpoint ensures that the cell is ready to complete mitosis

Question 6

describe the G1 phase

Answer 6

cells grow and increase in size
transcription of RNA
protein synthesis and synthesis of some DNA enzymes
organelles duplicate
the p35(tumor suppressing) gene helps control this hase

Question 7

what’s the purpose of the G1 Checkpoint

Answer 7

its a control mechanism which ensure the cell is ready to enter the S phase and begin DNA synthesis.

Question 8

describe the G0 phase

Answer 8

its a phase within the G1 where cells undergo
differentiation
apoptosis(programmed cell death)
enter senescence (where they can no longer divide)

Question 9

describe the S phase

Answer 9

it is committed to completing the cell cycle
DNA replicates
each one consists of a pair of sister chromatid after duplication
This phase is rapid to prevent genetic mutation from happening.

Question 10

what are housekeeping genes and why are they replicated last?

Answer 10

Because they contain the genes that are active in every cell