Cell division Flashcards
What process do eukaryotes use to divide?
Mitosis and meiosis.
What process do prokaryotes use to divide?
Binary fission.
How can binary fission be calculated?
X x 2*Y
What does the cell cycle consist of?
Interphase, mitosis, cytokinesis.
Describe interphase.
Prepares cell for division.
G1-> cell grows, proteins synthesised to make new organelles later
Checkpoint
S-> DNA synthesised
G2-> cell grows, new organelles synthesised, ATP synthesised to increase energy store
Checkpoint
Describe mitosis.
Prophase-> Chromosomes condense and become more distinct by coiling up and thickening. Centriole divides and moves to opposite poles. Nuclear envelope disintegrates.
Metaphase-> Centriole produces spindle fibres that attach to centromere and pulls chromosomes to metaphase plate.
Anaphase-> Spindle fibres contact and ATP is used to pull chromatids to opposite poles.
Telophase-> Chromatids uncoil and become less distinct. Nuclear envelope starts to reform.
Describe cytokinesis.
When the cell divides. Cytoplasm and surface membrane split.
What is G0?
When a cell comes out of the cycle to avoid replication either temporarily or permanently due to damage or certain differentiation.
How to work out mitotic index?
number of cells with visible chromosomes/number of cells visible
What is cancer?
Result of mutations or damage in regulatory genes controlling the cell cycle.
What is a tumour and its types?
A mass of cells undergoing uncontrolled cell division. Benign, malignant.
How are tumours measured and why?
Measured by volume because they do not grow uniformly.
Describe benign tumours.
Non cancerous, capsule surrounding to keep compact, produces adhesion molecules that stick cells together and to tissues. Localised impact.
Describe malignant tumours.
Cancerous, do not produce adhesion molecules, can form own capillary networks to divide and spread faster through metastasis.
What is metastasis?
The breaking off and spreading of a tumour.
