1. Mitosis

2. What is the most important part of a cell when it wants to divide?
What important “stuff” is inside the nucleus?
NUCLEUS!!!
DNA!!

3. What role does DNA play in our cells?
It tells your cell how to act and what to become

4. What is DNA made up of? What does DNA look Like?
Nucleic Acid
What does DNA look Like?
DNA looks like spaghetti in the cell
In this form it is called chromatin
DNA can wind up on itself to form chromosomes
46 chromosomes in human cells

5. Human Karyotype

6. Human Karyotype Shows many chromosomes are present
Shows chromosomes with their pair
One from mom and one from dad
Also can identify gender
Y Chromosomes are much smaller
XX = female (two long chromosomes)
XY = male (1 short and 1 long chromosome)
Can use karyotypes to identify chromosomal abnormalities (trisomy 21)

7. Chromosome Parts Sister chromatids (identical copies)
Single stranded chromosome
Double stranded chromosome – It has gone through DNA replication
Sister chromatids
(identical copies)

8. Why Do Cells Reproduce?
To make new cells in order to grow and repair itself

9. Cell Cycle
A repeating process of cell growth and division

10. CELL CYCLE
Interphase
A cell spends 90% of it’s life in interphase.

11. 3 Phases of Interphase G1- First growth phase S phase- DNA copied
G2- Second growth phase

12. Mitosis (M) Phase The nucleus and DNA divide
Mitosis is divided into phases:
Prophase
Metaphase Anaphase
Telophase

13. What Cell Parts Are Involved?
Nuclear Membrane
Cytoplasm
Nucleus
Chromosomes
(DNA)
Cell Membrane
Centrioles

14. Prophase
Nuclear Membrane
Centriole
Chromosomes
Spindle Fibers

15. Prophase Chromosomes thicken Nuclear membrane begins to disappear
Spindle fibers start to form between the centrioles

16. Metaphase
Centriole
Chromosomes
Spindle Fibers

17. Metaphase Chromosomes line up across middle
Spindle fibers are attached to each chromosome (at the centromere)

18. Anaphase
Centriole
Chromosomes
Spindle Fibers

19. Anaphase Centromeres divide
Sister chromatids are pulled toward opposite ends of the cell

20. Telophase
Nuclear Membrane
Centriole
Chromosomes
Furrowing

21. Telophase Nuclear membrane begins to re-form
Chromosomes uncoil (becoming less visible)
Furrowing occurs

22. Cytokinesis
Cytoplasm divides and two separate daughter cells are produced

23. Mitosis Each cell now has 46 chromosomes (same it started with)
Each new cell grows until it is ready to divide

24. Mitosis All body cells in humans are made through mitosis
Sex cells (egg & sperm) are NOT made through mitosis

25. Put It All Together!!! Animal Cell Mitosis

26. All Cells are Different!!
All cells live for different lengths of time
Cells carry out mitosis at different speeds to replace cells that are worn out
Brain cells yrs
Red Blood Cells days
Platelets days
Stomach Lining days
Cells
Liver Cells days
Intestine Lining days
Skin cells days

27. Mitosis
In which body organs do cells carry out mitosis the most often?
Stomach, Intestine, Skin
In which body organs do cells carry out mitosis the least often?
Brain

28. Plant vs. Animal Cell Mitosis
Plant cells do not have centrioles
There is no furrowing in telophase. A cell wall forms instead.

29. Put It All Together!!! Plant Cell Mitosis

30. Flaws in Mitosis
When cells are dividing out of control, tumors are produced
Cancer is one type of tumor that can result from out of control mitosis

31. Mutations Mutations = random mistakes in DNA copied during Interphase
Can result from UV radiation, genetics, smoking, etc.