1. The Continuity of Life
Mrs Tagore

2. Key words: Histone proteins Centromere Karyotype Homologous Autosome
Heterosome
Sex chromosomes
Haploid
Diploid
Somatic cell
Locus/loci
Homologous chromosomes
Alleles
Plasmid
nucleoid

3. Chromosomes and Eukaryotes
Read pages 15-16

4. Chromosomes and Eukaryotes
Read pages 15-16

5. Chromosomes and Eukaryotes
Read pages 17-18

6. Chromosomes of Prokaryotes
Read pages 18-19

7. Questions Complete questions 1-10 for tomorrow.
We will be discussing these in class, so I’ll be checking that you have done it!!

8. Title: Mitosis
Learning question: What are the names of the stages of mitosis?
Hook:
What connects these pictures?
(Can you write more than one word?!)

9. Lesson Aims Describe the cell cycle
Understand that mitosis is only one small part of the overall cell cycle
State the events that occur at each phase of the cell cycle
Describe each stage of mitosis
Identify each stage of mitosis from diagrams and micrographs

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

11. Cell division
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

13. Mitosis
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.

14. DNA ‘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

15. Chromosomes 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 pairs

16. This (imaginary, example) animal has just two pairs of chromosomes Red = Maternal Blue = Paternal
Give out paper chromosomes and an A3 cell outline
1p m p 2m

17. 1p + copy 1m + copy 2p + copy 2m +copy
During Interphase, each chromosome replicates and produces an exact copy of itself:
Using cut out chromosomes and paperclips, get students to produce tetrads as above
1p + copy m + copy p + copy m +copy

18. There are four stages to Mitosis
Prophase
Metaphase
Anaphase
Telophase
Remember though that this is a continuous process P M A T

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

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

21. Metaphase Chromosomes line up centromeres on equator of cell
Centrioles form spindles

22. Anaphase
Spindles ‘grip’ centromeres and chromosomes migrate to poles

23. Telophase Nuclear membranes reform Chromosomes disperse
Cytokinesis begins

24. Interphase
Both daughter cells are exact copies of the parent cell

25. INTERPHASE
MITOSIS

26. Stages of Mitosis

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

28. Name the stages!

29. Binary fission

30. Binary fission Prokaryotes reproduce by binary fission
No nucleus, centromere or chromosomes, therefore no mitosis
Two daughter cells produced
Cell replication>new DNA attaches itself to different part of cell membrane>cell pulls apart separating replicate and original DNA> wall forms dividing cells into two cells with identical genetic composition
Mitochondria and chloroplasts also use binary fission to form new organelles