Mitosis and meisos
- Created by: Freya Woolley
- Created on: 17-10-15 12:07
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- Mitosis + Meiosis
- Mitosis
- Cell division that makes animal and plants grow
- How old and damaged cells are replaced
- A Parent Cell divides into 2 identical daughter cells
- 1. Chromosomes are found in the nucleus
- 2. Chromosomes duplicate to chromatids- long and thin
- 3. Chromatids condense, join together at centromere
- 4. Spindle fibres (proteins) stretch from each side of the cell and attach to the centromere. Arranges chromatids in the centre of the cell
- 5. Spindle fibres contract, pulling the 2 chromatids apart. Nuclear envelope reforms around each set and the cell starts dividing
- 6. Cell finishes dividing in 2 and the chromosomes become longer and thinner.
- 5. Spindle fibres contract, pulling the 2 chromatids apart. Nuclear envelope reforms around each set and the cell starts dividing
- 4. Spindle fibres (proteins) stretch from each side of the cell and attach to the centromere. Arranges chromatids in the centre of the cell
- 3. Chromatids condense, join together at centromere
- 2. Chromosomes duplicate to chromatids- long and thin
- Produces DIPLOIDS -46 chromosomes
- Meiosis
- Gametes are produced
- Half the number of chromosomes (reduction division)
- Produces 4 unique daughter cells
- Ensures natural variation within a species
- Small parts of homologous chromosomes cross over, this exchange of genetic material increases variation
- 1st round of division- Homologous pairs of chromosomes align in the middle of the parent cell and separate
- The cell divides so each new daughter cell only contains 1 chromosome from each pair (23 in total)
- 2nd round- In each cell, the chromosomes align at the centre + its chromatids pulled apart into separate halves of the cell
- Each cell divides again, so each cell only contains 1 chromatid form each chromosome
- 2nd round- In each cell, the chromosomes align at the centre + its chromatids pulled apart into separate halves of the cell
- The cell divides so each new daughter cell only contains 1 chromosome from each pair (23 in total)
- Mitosis
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