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

Define:
apoptosis- the body's normal way of getting rid of uneeded or abnormal cells

telomeres- a region of repetitive DNA at the end of a chromosome

metastisis- the spread of a disease from one organ to another

tumor- and abnormal mass of cells that results when cells divide more rapidly than they should
or do not die when they should

proto-oncogenes- code for proteins that help regulate cell growth and differentiation

oncogenes- mutation in a proto-oncogenes, cell divides without a signal to do so

growth factor- a substance made by the body to regulate cell division and cell survival

tumor suppressor gene- a pair of genes that causes the cell to make a protein that controls cell
growth, cancer may result if there is a mutation in this gene

oncology- the study of cancer

carcinoma- cancer that begins in the skin or tissues that line organs

sarcoma- a cancer of any connective or supportive tissue, such as bone or fat

leukemia- cancer that begins in the blood-forming tissue, such as bone marrow. It causes a large number of
blood cells to be produced and spread.

lymphoma- cancer that begins in cells of the immune system

1. What do cancer cells look like?
Cancer cells have an enlarged nuclei and abnormal chromosomes. They do not looklike a normal specialized cell
Their chromosomes may be duplicated or deleted. Genes in cancer cells may have extra copies as well.

2. What is unusual about the nuclei of cancer cells?
The nuclei is is enlarged.

3. Why don't cancer cells die?
Cancer cells do not go through apoptosis, or the way abnormal cells usually kill themselves.
Instead cancer cells continue to multiply even though they are abnormal.

4. Describe the three phases of the development of cancer.
The three phases include the initiation, the promotion, and the progression. In the initiation a single
cell experiences a mutation and begins to divide. In promotion a tumor develops, and cells continue
to mutate. Finally in progression, a cell mutates in a way that gives it an advantage against other cells
until it is able to invade nearby tissue.

cell_cycle.jpg

5. Mutations in what two types of genes lead to uncontrollable growth?
Mutation in proto-oncogenes, or genes that code for proteins that encourage the cell cycle and discourage
apoptosis lead to uncontrollable growth. Tumor-suppressor genes, or genes that code for proteins that do the
opposite of proto-oncogenes also lead to uncontrollable cell growth.

6. What is p53? How does it cause cancer?
p53 is the protein in ells that activates genes that stop the cell cycle and promote apoptosis if repair of a cell
can't be accomplished.

7. What is RB? How does it cause cancer?
RB is a protein that turns on genes that bring about the cell cycle. It can allow cells to multiply too quickly.

8. What are the most common cancers cases for males and females?
The most common cancer cases for males are prostate, lung and colon and rectum. The most common caner
cases for women are breast, lung and colon and rectum.

9. What are the most common cancer deaths for males and females?
The most cancer deaths in men are caused by lung, colon and rectum, and prostate cancer. The most common
cancer deaths for females are caused by lung, breast, and colon and rectum cancer.

LungCancer.gif


colon_cancer.jpg