2. Title: Mitosis 8 th January 2014 Learning question: What are the names of the stages of mitosis? What connects these pictures? (Can you write more than one word?!) Homework: Complete exam questions by Wednesday15 th January Hook:

3.  (d) outline the processes taking place at the G 1 and G 2 points in the cycle;  (e) describe the appearance of the components of the nucleus and cell during mitosis with reference to: nuclear envelope, centrioles, spindle fibres, centromere, chromatids and chromosomes;

4. Key words… Mitosis Prophase Metaphase Anaphase Telophase Microtubules Cytokinesis Chromatid Chromasome Centromere Centriole Diploid

5. All complex organisms originated from a single fertilised egg. Every cell in your body started here, through cell division the numbers are increased. Cells then specialise and change into their various roles

7.  Mitosis is the process by which new body cell are produced for: ◦ Growth ◦ Replacing damaged or old cells. This is a complex process requiring is to be split into different stages to understand it.

8.  ‘Blueprint of life’  Codes for all the proteins needed for life  Describes that characteristics of every living thing  Every cell with a nucleus contains ALL the instructions to make the organism  http://www.pbs.org/wgbh/nova/photo51/me dia/journey.swf http://www.pbs.org/wgbh/nova/photo51/me dia/journey.swf

9.  Each DNA strand is split into chromosomes  All sexually reproducing animals have pairs of chromosomes. One set of each pair comes from each parent ◦ Humans have 23 pairs ◦ Lions have 19 pairs ◦ African wild dogs have 39 pairs ◦ Mosquito have 3 pairs ◦ Some ferns have 500-600 pairs

10. 1p 1m 2p 2m

11. 1p + copy 1m + copy 2p + copy 2m +copy

12.  Prophase  Metaphase  Anaphase  Telophase  Remember though that this is a continuous process PMATPMAT

13.  Standard condition of cell  DNA replicates  Cell enters reproductive cycle with 2 copies of each chromosome

14.  DNA super coils and chromosomes become visible  Nuclear membrane breaks down  Centrioles migrate to poles

15.  Chromosomes line up centromeres on equator of cell  Centrioles form spindles

16.  Spindles ‘grip’ centromeres and chromosomes migrate to poles

17.  Nuclear membranes reform  Chromosomes disperse  Cytokinesis begins

18.  Both daughter cells are exact copies of the parent cell

19. INTERPHASE MITOSISMITOSIS

20.  http://www.cellsalive.com/mitosis.htm http://www.cellsalive.com/mitosis.htm

21. 1. In humans, each cell (except sex cells) has how many chromosomes? ______ 2. After mitosis, how many daughter cells are produced? _______. After mitosis (in a human cell), each daughter cell has how many chromosomes? _____ 3. How many phases are in MITOSIS? ___________ 4. Which phase of the cell cycle is the longest? _________ 5. During which phase does cytokinesis begin? __________ 6. What cell parts migrate to the poles during prophase? __________________. 7. What structure holds the two chromatids together? ____________________ 8. During which phase does the nuclear membrane dissolve? __________________ 9. What structure moves the chromosomes into position and then pulls them apart? ___________________ 10. What is the overall purpose of mitosis? _________________________ 11. Complete textbook Q1-3

22.  Which stage?

23.  (d) outline the processes taking place at the G 1 and G 2 points in the cycle;  (e) describe the appearance of the components of the nucleus and cell during mitosis with reference to: nuclear envelope, centrioles, spindle fibres, centromere, chromatids and chromosomes;