Biology SL chapter 2.5 (Cell division)

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  • Created by: Ninewatts
  • Created on: 05-04-15 11:38
Outline stages of cell cycle
Interphase (G1, S, G2), Mitosis and cytokinesis
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Interphase
Stage of development between two successive M-phases. 3 Stages, (G1,S,G2), G1: growth, S: DNA replication, G2: prepares for divions
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Causes of tumours
The cell cycle is controlled by chemical control systems. Tumour suppressor genes produce proteins which inhibit cell division. Mutations in these genes cause uncontrolled cell division, creating a tumour which damages local tissues.
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What happens during interphase? (PAID)
Protein synthesis: cell syhtesises proteins and enzymes which enable it to grow. ATP production: cell needs ATP to divide. Increase number of organelles. DNA replication
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Growth checkpoints of interphase
None of the PAID reactions occur in m-phase, therefore interphase contains growth checks to ensure viability of division. G1: Cell grows, duplicates organelles, synthesises protein and ATP. S: DNA is replicated. G2: DNA is checked for mutations
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Phases of mitosis
Prophase, metaphase, anaphase, telophase
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Prophase
1.DNA coils, creating chromosomes (made from sister chromatids joined at centromere).2. Centromeres move to opposite poles and spindle fibres begin to form. 3. Nuclear membrane disappears.
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Metaphase
1.Spindle fibres from centrosomes attach to centromeres of each chromosome. 2. Chromosomes are lined up along the centre of the cell (metaphase plate)
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Anaphase
1. Continued contraction of spindle fibres causes sister chromatids to separate and move to opposite poles of the cell.
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Telophase
1. Once two sets of identical chromosomes arrive at poles, spindle fibres dissolve and new nuclear membrane forms. 2. chromosomes decondense. 3. Cytokinesis happens.
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How does mitosis produce two genetically identical nuclei?
In S phase, DNA was replicated to produce 2 copies of genetic material. These two DNA molecules are sister chromatids held together by a centromere. During mitosis, sister chromatids are separated. After cytokinesis, each nuclei has 1 chromatid pair
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Four bodily functions that involve mitosis (GATE)
Growth (multicellular organisms increase in size), Asexual reproduction (eukaryotic organisms may produce asexually), Tissue repair (dead or damaged cells are replaced), Embryonic development (Fertilized egg undergoes mitosis to become an embryo
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Other cards in this set

Card 2

Front

Interphase

Back

Stage of development between two successive M-phases. 3 Stages, (G1,S,G2), G1: growth, S: DNA replication, G2: prepares for divions

Card 3

Front

Causes of tumours

Back

Preview of the front of card 3

Card 4

Front

What happens during interphase? (PAID)

Back

Preview of the front of card 4

Card 5

Front

Growth checkpoints of interphase

Back

Preview of the front of card 5
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