Week 6

Part A(Questions 1-4 should be a min of 400 words)
1. How do you think it would harm your body if your cells did not replicate their DNA before going through mitosis?

2. How do you think it would affect your offspring if homologous chromosomes were not separated during meiosis?

3. Cancer typically requires five mutations in DNA before uncontrolled cell division occurs.
How might one’s behavior, body type, diet, and/or environment affect the risk of cancer?
Could a combination of these factors occur in one individual?
Provide a possible scenario.

4. Find out how tanning booths affect the risk of skin cancer by searching the Internet.
Based on what you discovered how might this affect one’s feelings about the use of a tanning bed?
Provide the link to one source you found.

Part B

Please answer the following questions. Answers must be submitted in a Word document. Please number each answer as numbered in the questions.
1. Choose a nondisjunction disorder and write five sentences about it. Make sure you mention which chromosome is involved (for example, chromosome 18) and what kind of effects the disorder has on the human body.

Name of the non-disjunction disorder: __________________ Chromosome #____ 1 point

Sentence 1__________________________________________________________1 point

Sentence 2__________________________________________________________1 point

Sentence 3__________________________________________________________1 point

Sentence 4__________________________________________________________1 point

Sentence 5__________________________________________________________1 point

2.. Epithelial tissue, bone tissue, and blood are similar in that they have a high rate of mitosis—epithelial tissue is constantly being replaced, red blood cells are continuously produced in bone marrow, and osteoblasts actively produce bone.

Why are these tissues susceptible to cancer (e.g., skin cancer, lung cancer, leukemia)?

3.. DNA is a very long molecule that can be difficult to fit into a nucleus. Describe how nucleosomes help solve this problem. 4 points

4. During the cell cycle, during which phase does growth occur? 2 point

What impact does this have on the size of the daughter cells at the end of mitosis? 2 point

What impact does this have on the size of the daughter cells at the end of meiosis? 2 point

5. Consider the gene for hairline, which has two alleles, one for straight hairline and one for a widow’s peak hairline. If a woman has both alleles in her body cells, what will her eggs contain? 2 point

6. In oogenesis, only one daughter cell per meiotic event is fully developed into an egg.

Why might this be?