1. Malignant Melanoma Shocking and True !
The deadliest and most common form of cancer…
Malignant Melanoma

2. Think about it: Answer these questions in your notebook
How do you think cancer develops?
How did you grow from one cell to trillions? (Yes, you are made of A LOT of cells)
When you get a cut how does your skin heal ?
Think about it:

3. Cell Growth
Most organisms grow by producing more cells, not by producing larger cells

4. There are two main reasons why cells divide
1. Repair
Cells become Damaged/Cells have reached their life span
2.Growth/Development
Organisms GROW by making more cells not by making their cells larger
The larger a cell becomes, the more demands the cell places on its DNA
Also, a larger cell has more trouble keeping up with the needs of the cell
moving nutrients in and
exporting wastes out through the cell membrane

5. The process by which cells divide
Cells divide to form two “identical daughter” cells
This is called cell division
allows organisms to grow larger while, allowing cells to remain small
Before a cell divides it must copy its genetic information, so each daughter cell can get a copy

6. The cells genetic information is carried by the chromosomes
Chromosomes are composed of bundles of DNA
Cells of different organisms have different numbers of chromosomes
Fruit fly cells have 8 chromosomes
Carrot cells have 18 chromosomes
Human cells have 46 chromosomes

7. The DNA of a cell is not visible until it begins to condense into chromosomes for cell division
Before DNA condenses into chromosomes it is replicated
The copies condense into two identical sister chromatids
Attached at an area called the centromere
When the cell divides these sister chromatids separate so that each new cell formed gets one set of chromosomes

8. The cell cycle
The steps that a cell goes through as it grows and divides
What happens in the cell cycle?
the cell grows
Prepares for cell division
Divides to form two identical daughter cells
These new cells begin the cycle again
The cell cycle consists of four phases

9. G1 phase is where cell growth occurs
The first group of phases is called interphase and has three stages
G1 phase is where cell growth occurs
S phase follows and is where DNA gets replicated and proteins associated with chromosomes are synthesized
G2 phase is where organelles and molecules required for cell division are produced

10. The time frame for the cell cycle
Most of the cell cycle is spent in interphase
The last phase is called the M phase
This phase consists of mitosis and cytokinesis
Mitosis is divided into four steps
Cytokinesis is the final step for dividing 1 cell into 2

11. Step one of mitosis is prophase
Centrioles produce spindle fibers that separate the sister chromosomes later on in mitosis
Nucleolus disappears and nuclear envelope breaks down
Chromosomes condense and become visible and form structures like this

12. Step 2 of mitosis is metaphase
The chromosomes line up across the center of the cell
Spindle fibers are connected to each chromosome

13. Step 3 of mitosis is anaphase
Centromeres that join the sister chromatids splits
Chromatids separate and are pulled to either side of the cell by the spindles

14. Step 4 of mitosis is telophase
Condensed chromosomes begin to disperse
Spindle fibers break down
Nuclear envelope begins to develop around each set of separated chromosomes

15. At this time mitosis is complete but cell division is not completed
Remember that DNA is replicated in interphase (S phase)
Each copy is condensed and separated in mitosis (PMAT).
So……..
If the original parent cell has 4 chromosomes, then mitosis will produce 2 identical daughter cells that each contain 4 chromosomes.
THE NEW CELLS ARE EXACT COPIES OF THE ORIGINAL CELLS.

16. The second part of the M phase is called cytokinesis
This process divides the cytoplasm between the two newly formed nuclei (the nucleus)
In animal cells, the cell membrane is pinched in the center until it touches to form two separate cells
In plant cells, a cell plate forms between the two new nuclei and then a cell wall forms around it

17. CELL DIVISION IS NOW COMPLETE!!
You now have two IDENTICAL Daughter CELLS that came from one Parent cell.
Can you remember the 4 stages of the cell cycle?
Can you list the phases of the Mitosis and what is happening in each phase?

18. HOW DO I REMEMBER THE PHASES OF MITOSIS (cell division)
P-MAT
P-Prophase
M-Metaphase (M-middle)
A-Anaphase (A-Away)
T- Telophase
Cytokinesis (cell divides into 2)

20. Interphase Anaphase Prophase Telophase Cytokinesis
Visuals can help students make connections to the content and to unfamiliar words. My students use this every year. It helps to remind them of the sequence of the phases and also of the main processes that are occurring at each phase.
Cytokinesis
Metaphase
Use your Hands to help you remember. Can you describe what is happening in each phase?

21. STOP HERE FOR THE FOLDABLE.
DUE 12/3 Wed
Don’t forget to watch the Amoeba sisters and complete the handout. Due 12/3 Wed

22. Amoeba Sisters The Cell Cycle and Cancer video.
LETS WATCH

23. What controls cell growth and division so carefully?
Cells in a petri dish begin to divide
If some cells are removed from the center
Until they come in contact again
The cells bordering the open space begin to divide again
Until they fill the dish and come in contact on all sides and then stop dividing

24. The controls on cell growth and division can be turned on and off by the cells
One protein that regulates the timing of the cell cycle in eukaryotes is cyclins
Cyclins is an internal regulator
Several different regulatory proteins regulate different steps of cell division
Proteins that respond to events outside the cell are called external regulators
Growth factors are important external regulators during embryonic development and wound healing

25. Micro-experiments lead to the understanding of proteins that regulate cell division
A protein called p53 halts the cell cycle until all chromosomes have been properly replicated

26. Cancer A disorder in which cells lose the ability to control growth
Cancer cells do not respond to the signals that regulate growth
This can result in un-controlled growth
Can lead to tumors
Many different cancers have different causes but…
All have lost control over the cell cycle

28. Copy this into your notes!
Mitosis Vocabulary
Mitosis=cell division, a parent cell is copied and then divided to make two identical daughter cells.
Somatic cells (autosome = body cells)
Haploid=1set of chromosomes
Diploid (2n) = 2 sets of chromosomes
Asexual reproduction (clones, used for growth and repair)
Provide Examples of somatic cells: skin cells, muscle cells etc
Stress the results of cell division
Copy this into your notes!

29. Cells are real! Lets take a look right now!
We can see cells under a microscope.
We can see them dividing and even see their chromosomes!
Lets take a look right now!

30. But first….
…..lets talk about what we are going to look for in our slides.

31. Animal Mitosis -- Review
Cytokinesis
This is similar to what you will see in the fish slides

32. Plant Mitosis -- Review
Remind students about what processes are occurring at each phase.
Cytokinesis
This is similar to what you will see in the onion slides

33. Microscope Station View each slide.
Identify what phase of mitosis is occurring by talking to your group members.
In your lab notebook: Sketch the phases seen in each slide in the correct order.
Remind students about what processes are occurring at each phase.

34. START YOUR NOTES FOR MONDAY 12/7 here

35. Meiosis, the production of sex cells
Genes are located on the chromosomes in the cell nucleus
All cells have two sets of genes, a single copy from each parent
These are homologous (the same) and the pair make a diploid cell
Reproductive cells are called gametes and contain only one set of genes; so they are haploid

36. Meiosis is the process of reduction division that cuts the number of chromosomes in half
It does this by separating the homologous chromosomes in a diploid cell.
Meiosis has two distinct divisions; Meiosis 1 and Meiosis 2
Meiosis 1 is similar to mitosis, this example follows two chromosomes
The big difference between meiosis 1 and mitosis is that during prophase 1 of meiosis, the replicated homologous (identical) chromosomes pair up to form a tetrad
There are 4 chromatids in a tetrad that contain one identical copy of each of the original pairs of chromosomes from the diploid cell

37. In anaphase 1 of meiosis, the homologous chromosomes separate and two new cells are formed
If the original cell was heterozygous this can create two unique cells
Crossing over is a process that occurs when chromosomes of the tetrad rub into each other and exchange genetic material (Occurs during Prophase 1)
Crossing over makes the new cells unique as the chromosomes exchange alleles (genes) while rubbing together

38. The two new cells formed in meiosis I now have a set of chromosomes that are different from each other. The next step is meiosis II
Here, replication does not occur before the next cell division
In anaphase II, the paired chromatids will separate, this reduces the number of chromosomes in the new gamete cells by half

39. The cells will go through telophase and cytokenesis to produce four haploid cells called gametes (sex cells, egg or sperm)
These will be the reproductive cells
The reproductive gamete cells produced in males are called sperm
The reproductive gamete cells produced in females are called eggs
Meiosis results in the formation of 4 different haploid cells

40. Recap Meiosis is The division of sex cells There are 4 cells created
Each cell is genetically unique (different)
Each cell only has half the number of chromosomes needed to make an organisms
There are two major phases of meiosis (meiosis 1 and meiosis 2)
Meiosis 1 is similar to mitosis (PMAT) but in prophase 1 the chromosomes cross over (exchange genetic material)