1. Cancer, Haploid/Diploid Cells and Somatic/Gametic Cells
Biology
K. Beris

2. Normal and Abnormal Cell Growth
Enzymes control cell division
Cancer: Cell death or uncontrolled cell growth (or uncontrolled dividing of cells)
Caused by a lack of or too much of enzymes
Caused by defective genes
Thought to be caused by changes in genes controlling mitosis

3. Normal and Abnormal Cell Growth, cont.
Contact inhibition
Cells stop dividing when they come in contact with each other
Abnormal cells continue to grow
They form masses of tissues called tumors
Cancer cells mass of tissue  tumor
If malignant, the cancer can spread

5. Normal and Abnormal Cell Growth, cont.
Causes of cancer:
Anything that damages the genes that control the cell cycle
Cigarette smoke
Air and water pollution
UV radiation

6. Differences between Diploid and Haploid Cells
Each species has a certain number of chromosomes
Example: Humans have 46 chromosomes
Homologous chromosomes
Pairs of chromosomes with similar information
Example: humans have 23 pairs of homologous chromosomes (23 from each parent)

7. Differences between Somatic and Gametic Cells
Somatic Cells
Body cells
Contain two of each chromosome
Diploid number
Example: human somatic cells have 46 chromosomes (the diploid #)
Gametic Cells:
Sex (reproductive) cells
Contain only one of each chromosome
Haploid number
Example: human gametes only have 23 chromosomes (haploid #)
Male gamete—sperm
Female gamete—egg or ovum