1. Cell Cycle
Does an animal get larger because each cell increases in size or because it produces more of them?

2. Cell Growth
As you might have guessed, living things grow by producing more cells.
The koalas have the same size cells, just one has more then the other.

3. Cell Growth
Mature red blood cells are not capable of dividing, as they do not possess nuclei. Therefore, it is not possible that red blood cells will divide as they travel along our blood vessels. New red blood cells are produced in the red bone marrow of long bones in adults, not from the cell division of mature red blood cells. "RBCs are terminally differentiated; that is, they can never divide. They live about 120 days and then are ingested by phagocytic cells in the liver and spleen."

4. Why DO Cell’s Divide ..
The reason cells divide is because as volume increases:
More demand is placed on cell’s DNA (DNA Overload)
More difficult to bring in enough nutrients and get rid of waste (material exchange)
Ratio of surface area to volume
Overtime many of the cells die and need to be replaced.

5. Chromosomes
In eukaryotic cells, the genetic information that is passed on from one generation of cells to the next is carried by chromosomes.
The cells of every organism have a specific number of chromosomes.
Chromosomes contain both DNA and protein tightly packed together to form chromatin.
Right before cell division each chromosome is replicated, Each chromosome consists of two identical “sister” chromatids.
When the cell divides, the “sister” chromatids separate and go to each of the new cells.

6. Chromosome
Each pair of chromatids is attached at an area called a centromere.
Centromeres are usually located near the middle of the chromatids, although sometimes can be found at each end.

7. CELL CYCLE
The process by which a cell reproduces to create two identical copies is known as mitosis.
Cells formed by mitosis are known as daughter cells.
The cell division process occurs in several different stages, known collectively as the 'cell cycle'.

8. Cell Cycle
The cell cycle consists of four stages  G1, S, G2, and M and then cytokenesis.
G1 and G2 are 'gap' phases.
G1 (gap 1) phase (primary growth phase) –cell gets bigger
S phase is the synthesis phase in which the chromatin (DNA) is copied (replicated).
G2 (gap 2) –cell prepares to divide, organelles replicate
M is the mitotic phase in which the cell physically divides into two daughter cells. Has 4 sub-phases!
Most cells are NOT actively dividing. These cells are in a resting state (G).

10. Mitosis (M phase) steps which include the process for asexual cell division.
Biologists divide the events of mitosis into four phases:
Prophase
Metaphase
Anaphase
Telophase
Depending on the type of cell, the four phases may last anywhere from a few minutes to several days.

12. PROPHASE
The first and the longest phase of mitosis, prophase can take as much as 50 to 60 percent of the total time required to complete mitosis.
centrioles form and move to opposite ends
spindle fibers form
Chromosomes condense and become visible
nuclear membrane breaks down

13. METAPHASE chromosomes line up in the middle of the cell
Chromosomes attach to spindle fibers

14. The kinetochore is the protein structure on chromosomes where the spindle fibers attach during cell division to pull the chromosomes apart.
The kinetochore forms in eukaryotes, assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis.

15. ANAPHASE Sister chromatids separate and move toward opposite poles
Each new chromatid is now called a chromosome.
(Hint if there is a centromere, it is a chromosome)

16. TELOPHASE Chromosomes gather at opposite ends and start to unwind
Spindles break down
Nuclear envelopes re-form at the two poles
New cell membranes begin to form to create two independent cells

17. CYTOKINESIS the division of the cytoplasm to make two complete daughter cells
ANIMAL CELLS
Cell membrane pinches apart into two equal parts with one nucleus in each daughter cell
PLANT CELLS
Cell plate forms between two nuclei
Cell plate develops into a cell wall

19. Animations http://www.johnkyrk.com/mitosis.html

20. Activity Pass out white boards to students (groups of 2-3)
Flip through the following slides and have students either draw or label the picture

21. CYTOKINESIS

24. METAPHASE

27. PROPHASE

29. ANAPHASE

31. Cell Cycle Regulators
Scientists discovered that cells in mitosis contain a protein called cyclin when injected in a non-dividing cell, would cause a miotic spindle to form.
Cyclins regulate the timing of the cell cycle in eukaryotic cells.
Many of the abnormal traits of cancer cells are due to defects in genes that control cell division.

32. Uncontrolled Cell Growth
Why is cell growth regulated so carefully?
Cancer- a disorder in which some of the body’s own cells lose the ability to control division. Cancer cells do not respond to the signals that regulate the division of most cells.