1. Bell ringer What is an organelle?
What are the organelles present in a prokaryote? Why would an organism need to make more DNA?
Wat is the process called of creating mRNA from DNA?
What process produces protein?

2. BELL RINGER What is the cell cycle?
What are the stages of the cell cycle?
What is produced in the cell cycle?
How can the cell cycle be corrupted?
What is produced when the cell cycle is cprrupted?

3. Bell Ringer What are four reasons the cell needs to divide?
When does DNA Replication occur in the cell cycle?
Why does DNA replicate?

4. Bell Ringer- HAPPY VALENTINES DAY
What phase of mitosis is occurring in the cell indicated by the arrow?
What phase of mitosis is occurring in the cell indicated by the cell in the circle?
What is the order for a
normal skin cell going
thorough its life cycle?

5. Cell Cycle
Growth + Division

6. Cell Cycle
What is it?
Why do cells do it?
Why is it important to me?

7. Why do cells divide? For growth and development
From fertilized egg to adult
For repair and replacement
Replace cells that die from normal wear and tear or from injury

8. Where does the cell cycle take place?
In the somatic (body) cells of all living organisms.
Keeps cells living and growing.

9. What macromolecule?
DNA is a Nucleic Acid!
DNA!!!
Nucleotide

10. Parts of the Cell Cycle Interphase
The cell is growing
The cell synthesizes a copy of its DNA
Cell division (mitosis and cytokinesis)
The cell undergoes division
Results in 2 identical daughter cells

11. Interphase
The majority of the cells’ life is spent growing and preparing for division
During Interphase, 2 things happen:
A cell increases in size (grows)
The DNA is copied (duplicated)
Interphase not part of Mitosis!
Because mitosis deals with cell division, where interphase is the cell living day to day life, preparing for division.

12. Interphase – 3 phases Gap1 Phase = G1 Synthesis Phase = S
First GROWTH phase
Cell increases in size
Cell prepares to copy its DNA
Synthesis Phase = S
S = Synthesis
The cell “synthesizes” a copy of its DNA
How the cell maintains their chromosome number!!
Gap2 Phase = G2
Rapid cell growth and protein synthesis
Cell is preparing for mitosis

13. Interphase
Interphase
Interphase
Interphase

14. Checkpoints
In between each part of Interphase (G1, S and G2) there is a checkpoint
The cell is looking for errors
In most cases, if an error is caught 1 of 2 things occurs
The error is corrected and the cell proceeds to the next step
The error can’t be corrected and the cell cycle for that cell is shut down; the cell dies and is broken down
What happens if an error is not caught or a cell misses a checkpoint
Uncontrolled cell growth and division = Cancer
Tumors

15. Factors that effect DNA
Sunlight and UV Radiation
Skin Cancer
Smoking/ Carcinogen
Lung, throat, mouth cancer
Diet
Alcohol consumption = liver cirrhosis
Radiation
Microwaves
X-rays

16. Vocabulary
DIPLOID (2n) is the complete numer of chromosomes in a somatic (body) cell
CHROMOSOME is an organized section of DNA
It is a single piece of coiled DNA containing many genes
CHROMATID is one of the
identical 2 parts of the chromosome
SISTER CHROMATIDS are the
two identical parts of the chromosome
CENTROMERE is the point where
sister chromatids touch

17. Chromosome, Chromatid, Sister Chromatids and Centromere

18. Chromosomes
Chromatid
Centromere
Chromosome
Sister Chromatids

19. Cell Cycle – Part 2 = MITOSIS
Once the cell has finished interphase (G1, S, G2) it is prepared for the 2nd part of the cell cycle
MITOSIS: the preparation for division part of the cell cycle
Prophase
Metaphase
Anaphase
Telophase

20. Prophase DNA is wound up into chromosomes to keep it organized
This prevents errors when its time for the cell to separate into 2
Nuclear membrane disappears
Centriols (animal cells) migrate to
opposite ends

21. Metaphase
Chromosomes line-up in the middle of the cell along the “equator”
They are attached to SPINDLE FIBERS - proteins that help move the chromosomes during the division process

22. Anaphase Chromosomes are split
SISTER CHROMATIDS are pulled to Away from each other by the spindle fibers

23. Telophase Nuclear membrane starts to reappear in each daughter cell
Once the nuclear membrane has reformed, the chromosomes unwind back into the expanded DNA version (chromatin)

24. Cytokinesis (cyto = cell, kinesis = cutting)
The cytoplasm splits
2 identical daughter cells are formed
Each daughter cell has its set of organelles

25. Cytokinesis: Plant vs. Animal Cells
Plant Cells form a CELL PLATE
Animal cells form a CLEAVAGE FURROW

26. Cleavage Furrows vs. Cell Plates

27. I Please Make Another Two Cells
The Cell Cycle all put together….Interphase (growth) plus Mitosis (division) D
interphase
prophase
I Please Make Another Two Cells
cytokinesis
metaphase
anaphase
telophase

29. Why is the Cell Cycle Important?
All living organisms are made up of cells
Cells are the basic unit of structure/function of all living organisms
All cells come from pre-existing cells
You are a living organism made up of cells
In order to keep living your cells must keep living
In order for your cells to keep living, they must divide (to multiply)

30. So WHY do cells divide?
As cells get larger they put extra demand on their DNA
The bigger the cell gets it becomes harder to keep up with the demand for nutrients and to moves wastes out
This happens because the surface area to volume ratio does not stay the same as a cell increases in size

31. The cells ability to get nutrients in and wastes out is related to the surface area of the cell membrane
How much food and other material is required and how much waste the cell produces and has to get rid of is related to the volume of the cell
As a cell gets bigger there comes a time when the surface area of the cell membrane is not large enough to meet the demands of the cell’s volume
Sooo….at some point a cell has to divide in order to keep functioning

32. The cell cycle set to music…