1. Cell Cycle & Mitosis

2. Cell Division All cells are derived from pre-existing cells
New cells are produced for growth and to replace damaged or old cells

3. Keeping Cells Identical
The instructions for making cell parts are encoded in the DNA, so each new cell must get a complete set of the DNA molecules

4. DNA Replication DNA must be copied or replicated before cell division
Each new cell will then have an identical copy of the DNA
Original DNA strand
Two new, identical DNA strands

5. Identical Daughter Cells
Two identical daughter cells
Parent Cell

6. Prokaryotic Chromosome
The DNA of prokaryotes (bacteria) is one, circular chromosome attached to the inside of the cell membrane

7. Eukaryotic Chromosomes
Each chromosome is composed of a single, tightly coiled DNA molecule
Chromosomes can’t be seen when cells aren‘t dividing and are called chromatin

8. Eukaryotic Chromosomes
All eukaryotic cells store genetic information in chromosomes
Most eukaryotes have between 10 and 50 chromosomes in their body cells
Human body cells have 46 chromosomes or 23 identical pairs

9. Chromosomes in Dividing Cells
Duplicated chromosomes are called chromatids & are held together by the centromere
Called Sister Chromatids

10. Karyotype
A picture of the chromosomes from a human cell arranged in pairs by size
First 22 pairs are called autosomes
Last pair are the sex chromosomes
XX female or XY male

11. The Y Chromosome Decides
Boy or Girl?
The Y Chromosome Decides
Y - Chromosome
X - Chromosome

12. The Cell Cycle

13. Interphase = between phases
Chromatin
DNA Duplicates

14. G1 First growth phase - Cell grows in size Creates mRNA and proteins
Ends when the cell enters into the S phase

15. S PHASE
DNA is Replicated
S phase occurs between G1 and G2

16. G2 Cell continues to grow and create mRNA and proteins
Cell will duplicate organelles getting ready for the Mitosis phase

17. Mitosis Division of the nucleus Only occurs in eukaryotes
Has four stages
Doesn’t occur in some cells such as brain cells

18. Mitosis = New Cells Results in 2 identical daughter cells
4 chromosomes  4 chromosomes
Daughter
Daughter

19. Onion Root Tip Mitosis Pictures
Interphase

20. Prophase Latin = "For" Chromosomes (and copies) condense
Chromatid = copy
Nuclear Membrane dissappears
Centriole spindles form

21. Prophase

22. Chromosomes (with copies) line up
Metaphase
Greek = "Adjacent"
Nuclear Membrane gone
Centrioles Move
Spindles grow
Chromosomes (with copies) line up

23. Chromosomes (with copies) line up
Metaphase
Nuclear Membrane gone
Centrioles Move
Spindles grow
Chromosomes (with copies) line up

24. Metaphase

25. Anaphase
Latin = "Away"
Spindles contract
Copies pulled apart

26. Anaphase
Spindles contract
Copies pulled apart

27. Anaphase

28. Nuclear Membranes form
Early Telophase
Latin = "Distant, End"
Spindles gone
Nuclear Membranes form

29. Early Telophase

30. Nuclear Membranes are complete
Late Telophase
Nuclear Membranes are complete
Mitosis is complete.

31. Late Telophase

32. Cytokinesis
Cell splits

33. Cytokinesis

34. Quiz

35. Metaphase

36. Interphase = between phases
Chromatin
DNA Duplicates

37. Metaphase

38. Prophase

39. Anaphase

40. Telophase

41. Nuclear Membranes are complete
Late Telophase
Nuclear Membranes are complete
Mitosis is complete.

42. Mitosis = New Cells Results in 2 identical daughter cells
4 chromosomes  4 chromosomes