MITOSIS- this is a type of nuclear division which produces 2 daughter nuclei that both have the same no of chromosomes as the parent cell.
A good way to remember the phases of mitosis is IPMAT. I remember it as: Important Person MAT, as this is one of my teachers names.
Spindle fibres:
Centromere: the central part of the chromosome that binds the chromatid pairs together (shown below)
A good way to remember the phases of mitosis is IPMAT. I remember it as: Important Person MAT, as this is one of my teachers names.
Spindle fibres:
- Attach to centromeres
- Contract to separate and move chromatid pair towards opposite poles
Centromere: the central part of the chromosome that binds the chromatid pairs together (shown below)
I-Interphase (remember inactive in terms of cell division)
P-Prophase (remember the chromosomes can only be pros when you see them)
M-Metaphase (remember you meet in the middle)
A-Anaphase (remember your anxious about separating)
division is nearly complete)
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THE CELL CYCLE-regular cycle of division separated by periods of cell growth. The 3 stages are:
1) Interphase- takes up the majority of the cell cycle. (Known as the ''Resting phase'' as no divison takes place).
This has 3 parts:
a) 1st growth/G1 phase- PROTEIN SYNTHESIS of cell ORGANELLES
b) Synthesis/S phase- DNA REPLICATION
c) 2nd growth/G2 phase- organelles grow & divide; ATP production
2) Nuclear division- when NUCLEUS DIVIDES by mitosis (into 2 cells) or meiosis (into 4 cells)
3) Cellular division- when the WHOLE CELL DIVIDES into 2 (mitosis) or 4 (meiosis)
The time it takes to complete the cell cycle varies between organisms. It typically takes a mammalian cell 24 hours.
1) Interphase- takes up the majority of the cell cycle. (Known as the ''Resting phase'' as no divison takes place).
This has 3 parts:
a) 1st growth/G1 phase- PROTEIN SYNTHESIS of cell ORGANELLES
b) Synthesis/S phase- DNA REPLICATION
c) 2nd growth/G2 phase- organelles grow & divide; ATP production
2) Nuclear division- when NUCLEUS DIVIDES by mitosis (into 2 cells) or meiosis (into 4 cells)
3) Cellular division- when the WHOLE CELL DIVIDES into 2 (mitosis) or 4 (meiosis)
The time it takes to complete the cell cycle varies between organisms. It typically takes a mammalian cell 24 hours.
Cancer:
Treatment of Cancer: The idea is to disrupt the cell cycle by blocking a part of it --> cell division & cancer growth ceases. This can be disrupted by drugs (chemotherapy) as it:
The problem with using drugs is that it can disrupt the cell cycle of normal cells. However the drugs are more effective against rapidly dividing cells. Cancer cells have a fast division rate than normal cells, so they are damaged to a much greater degree. TAKE THAT CANCER! However hair cells are also rapidly dividing, which is why we associate hair loss with chemotherapy. |
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MEIOSIS- nuclear division to form 4 haploid gametes