Mitosis and Meiosis Year 10 Biology Mitosis and

Mitosis and Meiosis Year 10 Biology

Mitosis and Meiosis • Mitosis: -division of somatic (body) cells • Meiosis -division of gametes (sex cells – sperm and eggs)

Mitosis • 2 identical daughter cells produced • Each daughter cell has the same number of chromosomes as the parent cell • 1 set of cell division involved • End result – 2 diploid (or 2 n) cells with 46 chromosomes in each

Mitosis • Interphase • Prophase • Metaphase • Anaphase • Telophase

Interphase • Interesting things happen! 1. Cell preparing to divide 2. Genetic material doubles (46 to 92)

Prophase • Chromosome pair up! 1. Chromosomes thicken and shorten -become visible -2 chromatids joined by a centromere 2. Nuclear membrane disintegrate 3. Spindle fibres form

Metaphase • Chromosomes meet in the middle! 1. Chromosomes arrange at equator of cell 2. Become attached to spindle fibres by centromeres

Anaphase • Chromosomes get pulled apart 1. Spindle fibres contract pulling chromatids to the opposite poles of the cell

Telophase • 1. 2. 3. 4. Now there are two! Chromosomes uncoil Spindle fibres disintegrate Nucleur membrane forms Cell divides

Meiosis • 4 daughter cells produced • Each daughter cell has half the chromosomes of the parent (halpoid or ‘n’) • 2 sets of cell division involved • End result – 4 cells with 23 chromosomes in each

Meiosis • Interphase Prophase II • Prophase Metaphase II • Metaphase Anaphase II • Anaphase Telophase II • Telophase