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Unit 6 - Coggle Diagram
Unit 6
Interphase
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Interphase: DNA is present as uncondensed chromatin (not visible under microscope), DNA is contained within a clearly defined nucleus, Centrosomes and other organelles have been duplicated, Cell is enlarged in preparation for division
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Prophase
Prophase: DNA supercoils and chromosomes condense (becoming visible under a microscope), Chromosomes are comprised of genetically identical sister chromatids (joined at a centromere), Paired centrosomes move to the opposite poles of the celland form microtubule spindle fibers, The nuclear membrane breaks down and the nucleus dissolves
Cyclins + CDKS
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Cyclins bind to the CDKs, and once they perform their functions, break down.
Checkpoints - allows the cell to pause in the cell cycle to fix any problems with the cell. Without them the cell might move through the cell cycle with damage.
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What happens at G1 checkpoint - Cells are checked for size, proper number of organelles and DNA is checked for mistakes
What happens at G2 checkpoint - Cells are checked for proteins needed for mitosis, and if the chromosomes were replicated correctly
What happens at the M checkpoint - Cells are checked to ensure that microtubules (spindle fibers) are connected appropriately to the chromosome
Metaphase: Microtubule spindle fibres from both centrosomes connect, to the centromere of each chromosome, Microtubule depolymerisation causes spindle fibres to shorten in length and contract. This causes chromosomes to align along the centre of the cell (equatorial plane or metaphase plate)
Anaphase: Continued contraction of the spindle fibres causes genetically identical sister chromatids to separate. Once the chromatids separate, they are each considered an individual chromosome in their own right. The genetically identical chromosomes move to the opposite poles of the cell
Telophase: Once the two chromosome sets arrive at the poles, spindle fibres dissolve, Chromosomes decondense (no longer visible under light microscope), Nuclear membranes reform around each chromosome set, Cytokinesis occurs concurrently, splitting the cell into two