1. Mitosis

2. Growth Increase in size-more cells
Cells possess internal controls over the process of cell division.
Each cell knows it’s size limitation.
Some cells like skin cells divide continuously
Heart and nerve cells reach a certain size, stop growing and rarely divide

3. CELL SIZE- How big can a cell get? 2 Factors limit cell size
1. DNA- can only control so much of the reactions within the cell(DNA contains instructions for protein manufacturing)
2. Surface Area vs. Volume- the cell volume increase faster than the surface membrane. Cell can’t make enough membrane fast enough.
SA increases to the 2nd power while volume increases to the 3rd power

4. CELL REPRODUCTION-MITOSIS
Results in formation of 2 identical daughter cells
Also called body or SOMATIC cells
Need to replicate cytoplasm and all of the organelles- including the chromosomes(coiled chromatin)
Chromatin- thin, uncoiled chromosomes and proteins called histone

5. Chromosome number
Each species has a certain set number of chromosomes- ½ from mom, ½ from dad.
Humans have 46 or 23 pairs.
Each chromosome contains genes that determine all the attributes of that organism from eye color to protein synthesis.

6. CELL CYCLE sequence of growth and division
2 STAGES 1.Interphase 2. A Mitosis :replication of nuclear material Prophase Metaphase) Anaphase Telophase 2.B. Cytokinesis

7. Interphase :G1-S-G2 G1-growth and development
S- DNA replication and important proteins produced
G2- new organelles and more RNA produced

8. 1. INTERPHASE Growth period Normal chromosome number- 46(23 pairs)
When CD is about to happen: the chromosomes duplicate- now have 92

9. 2.PROPHASE Longest phase Chromatin coils up Sister chromatids pair up
(original and copy)
Nuclear membrane and nucleolus disappear
Centrioles migrate to ends
Spindle forms(microtubules).Help pull chromatids apart. Other mt radiate out from pole- called asters.
Original and copy held together by centromere

10. CENTROMERE

11. 3. METAPHASE Shortest phase
Sister chromatids line up in the middle(equator)

12. 4. ANAPHASE
Chromosomes begin to separate with help of spindle fibers

13. 5. TELOPHASE Chromosomes reach opposite ends
Nuclear membrane begins to reform around each set of chromosomes
Chromosomes begin to loosen and return to chromatin
Cell has 2 nuclei

14. 6. CYTOKINESIS Division of cytoplasm Cell membrane reforms
End up with 2 identical cells
In plant cell- division of material along cell plate-becomes cell wall.

15. CONTROL OF CELL GROWTH
Accomplished by proteins called CYCLINS and enzymes
They must bind together in order to become active

16. Cancer Uncontrolled growth of a cell
Caused by : change in enzyme production or environmental cause which causes a change in the gene which leads to a protein change
This gene change causes uncontrolled growth which is now called cancer. The mass can grow large enough and deprive normal tissue of nutrients. Sometimes a cell from the mass breaks off and travels to other body part through the circulatory system (Metastasis)

17. Types of Cancer
Malignant- disease causing
Benign- no malignant

18. Cancer Causes Genetic(born with faulty gene)
Environmental- sunlight, smoking, chemicals
Viral infection- causes destruction of gene ( ex. Cervical cancer)