1. Cell Cycle and Mitosis

2. How do cells make more of themselves?
They go through the Cell Cycle
Remember each cell has the same DNA

3. What is DNA? DNA is the molecule that has hereditary information
Each person’s DNA is
different except for
identical twins

4. DNA- a double helix ( twisted ladder)

5. Cell Cycle Interphase- consists of 90% of the cell cycle 1)G 1
2) S phase
3)G2
M Phase- Mitosis

6. G1
Cell is growing

7. S phase
Cell is growing
DNA is replicated

8. G 2
Cell is growing

10. What is a chromosome?
When a cell is dividing, DNA winds up tightly and forms chromosomes in the nucleus of the cell.
Chromosomes- made of DNA and protein ( chromatin)

11. How many chromosomes do human have?
Humans – 46
Egg ( from female)- 23
Sperm ( from male) 23
Egg + Sperm = Human

12. Chromosome to Duplicated Chromosome

13. What is a gene?
A specific portion of the DNA code is called a gene, which has genetic information.
The genes are contained within the chromosome.

14. Important Vocabulary
Somatic cells (cells of the body) are diploid. This means that each cell has two chromosomes of each type. They are in PAIRS.
Gamete cells (egg, sperm) are haploid. This means that each cell has only one of each type of chromosome.
Biologists use “2N” to symbolize diploid.
Biologists use “1N” to symbolize haploid.

15. MITOSIS
cell division

16. MITOSIS Start: 1 cell End: 2 identical cells
Cell Reproduction: Division of the cell to make new cells.
Start: 1 cell
End: 2 identical cells

17. MITOSIS
4 PHASES/STEPS
NUCLEUS ONLY

18. Phases of Mitosis
P rophase
M etaphase
A napahse
T elophase

19. PROPHASE Nuclear membrane disappears.
Centrioles move to opposite sides of cell.
Chromosomes duplicate

20. PROPHASE

21. PROPHASE

22. METAPHASE Chromatids attach to spindle fibers and line up in
MIDDLE of cell.

23. METAPHASE
MILITARY LINE-UP

24. METAPHASE

25. ANAPHASE
Chromatids
Are pulled to
opposite
sides of
the cell.

26. ANAPHASE
AWAY

27. ANAPHASE

28. TELOPHASE New nuclear membrane surrounds Chromosomes, which return
to chromatin.

29. TELOPHASE
TWO NUCLEI

30. TELOPHASE

31. CYTOKINESIS
Cytoplasm splits

32. Differences in Cytokinesis
Animal Cell- Cytoplasm pinches in forming a cleavage furrow
Plant cell- forms a cell plate

33. Animal Cell Cytokinesis
Cleavage furrow forms

34. Plant Cell Cytokinesis
Cell plate forms between plant cells

35. CYTOKINESIS

36. CYTOKINESIS
2 CELLS

37. Always
Changing

39. CREATION OF 2 NEW IDENTICAL Body CELLS also known as somatic cells
WHOLE PROCESS:
CREATION OF 2 NEW IDENTICAL Body CELLS also known as somatic cells

40. Phases of Mitosis 4 phases: Prophase Metaphase Anaphase Telophase
Cytokinesis- division of the cytoplasm

41. Products of Mitosis
2 daughter cells that are Exactly the same