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Wiki Assignment on Cancer (Answers in Book--Chapter 19)

Define: apoptosis, is a programmed cell death. Ancer cells fail to undergo apoptosis even thought hey are abnormal cells. telomeres, just as shoelaces are capped by cmall pieces of plastic chromosomes in human cells end with special repetitive DNA sequences called telomeres. metastisis, when new tumors pop up that are far from the main tumor. tumor, Cancer cells that grown on top of eachtoerh in a pile. proto-oncogenes code for proteins that promote the cell cycle and prevent opoptosis. They are often likened to the gas pedal of a car becaue they cause acceleration of the cell cycle , oncogenes cancer causing genes, these mutations can be called gain of cuntion mutations because overexression is the result. , growth factor is a signal that activates a cell signaling pathway resulting in cell division some prot oncogenes code for a growth factor or for a receptor protein that receives a growth factor

, tumor suppressor gene, when tumor suppressor genes mutate their products no longer inhibit the cel cycle nor promote aopotosis therefore these mutations can be called loss of function mutations.

oncology, is the study of cancer and a medical specialist in cancer is, therefore known as an ocologist. carcinoma, tumors are classified according to their place of origin. Carcinomas are cancers of the eopthelial tissues and adenocarcinomas are cancers of glandular epithelial cells.

sarcoma, they are cancers that arise in muscles and connective tissue, such as bone and fibrous commective tissue

leukemia, they are cancers of the fibrous connective tissue lymphoma are cancers of lymphatic tissue.

1. What do cancer cells look like? Notice that oncogenes and mutated tumor suppressors genes have the same end effects: an unrestrained cell cycle, and apoptosis does not occur. They are stacked up and purple and piled up and unorganized.

2. What is unusual about the nuclei of cancer cells? They are so abnormal the nuclei of cancer cells are enlarged and may contain an abnormal number of chromosomes. The nuclei of the cervical cancer cells shown in figure 18 have increased to the point that they take up most of the cell.

3. Why don't cancer cells die? Cancer cells are immortal and keep on dividing for an unlimited number.

4. Describe the three phases of the development of cancer. INITIATION A SINGLE CELL UNDERGOES A MUTATION THAT CAUSES IT TO BEGIN TO DIVIDE REPEATEDLY PROMOTION A TUMOR DEVELOPS AND THE TUMOR CELLS CONTINUE TO DIVIDE. AS THE DIVIDE THEY UNDERGOE MUTATIONS. PROGRESSION ONE CELL UNDERGOES A UTATION THAT IVES IT A SELEVTIBE ADVANTAGE OVER THE OTHER CELLS. 5. Mutations in what two types of genes lead to uncontrollable growth? P53 and cyclin D

6. What is p53? How does it cause cancer? It’s a protein that turns on genes that stop the cell cycle and activates repair enzymes. If repair is impossible the p53 protein promotes apoptosis. 7. What is RB? How does it cause cancer? It is a retinoblastoma protein that turns on the gene for cyclin D and other genes whose products promote entry into the s phase of the cell cycle. 8. What are the most common cancers cases for males and females? Prostate for male and Breast for females. 9. What are the most common cancer deaths for males and females? Lung and bronchus for both