3B Flashcards
1
Q
what stages does the cell cycle consist of?
A
INTERPHASE:
G1 phase
S (synthesis) phase
G2 phase
M (MITOTIC) PHASE
Mitosis
Cytokinesis
2
Q
G1 phase
A
- organelles replicate
- transcription/translation
- size of cell increases
3
Q
S (synthesis) phase
A
- DNA synthesis
- chromosomes replicate
4
Q
G2 phase
A
- energy stores replaced
- transcription/translation
- chromosome repair
- size of cell increases
5
Q
mitosis
A
- chromosomes separate into two nuclei
- division of the nucleus
6
Q
cytokinesis
A
- cell divides into two
7
Q
stages of mitosis
A
- prophase
- metaphase
- anaphase
- telophase
8
Q
prophase
A
- chromosomes condense and become visible in nucleus
- each chromosome consists of 2 sister chromatids joined at centromere
- nucleolus disappears
- nuclear membrane starts to break down
- centrioles move to either pole of the cell
- spindle fibres form
9
Q
metaphase
A
- spindle apparatus has completely formed
- chromosomes are lined up at equator of the cell
10
Q
anaphase
A
- centromeres divide into two
- spindle fibres begin to shorten
- pulling sister chromatids towards opposite poles of the cell
11
Q
telophase
A
- chromatids have reached the poles of the cell
- referred as chromosomes
- spindle apparatus breaks down
- nuclear membranes reform
- chromosomes uncoil into chromatin state
- nucleolus reapperas
12
Q
cytokinesis
A
- central cell membrane is pulled inwards by cytoskeleton
- eventually membranes fuse, to form tow independent cells
13
Q
what does the mitotic index indicate?
A
the ratio between the number of cells in a tissue sample that are in mitosis and the total number of cells in the sample
14
Q
mitotic index
A
15
Q
how can the mitotic index be used to measure the effectiveness of treatments of cancer?
A
if the treatment is working, the mitotic index of the tumor will fall
