Biology Questions??

Question

Please help me. I have a test and can't find any of these answers in my textbook. Its very late and I really need to study the answers. Please help!!!


1. In what way do enzymes control the cell cycle?

2. What directs the production of these enzymes?

3. What can cause the cell cycle to become uncontrolled?

4. What can result when the cell cycle becomes uncontrolled?

5. What is the relationship between enviromental factors and cancer?

6. What is a tumor? Describe the final stage of Cancer?

Answer 1

1. Enzymes control the progress of the cell cycle. They keep it going at the right speed and keep everything happening at the right time.
2. DNA directs the production of these enzymes, just as DNA directs the production of all proteins in the cell.
3. The cell cycle can become uncontrolled when there is a mutation in the DNA, causing the enzymes to be produced in too great a quantity, not enough quantity, or the right enzymes produced at the wrong time.
4. When the cell cycle becomes uncontrolled, the cell cycle can go too fast and cells will divide entirely too quickly, over and over. The result can be cancer.
5. Environmental factors can cause cancer: chemicals, ultraviolet light, radiation, radon, asbestos, viruses, ...
6. A tumor is a mass of rapidly dividing cells.
Cancer robs the surrounding cells of food and oxygen, and cancer crowds normal cells and tissues. This keeps the normal cells and tissues from functioning properly. When cancers spread, a process called metastasis, the cancer cells travel to other parts of the body and tumors begin growing in organs throughout the body.

Answer 2

a tumor is a growth that is caused by mutations. most of the time its caused by outside factors such as the environment but it can also be due to genes. cancer is the accumulation of tumors due to carcinogens. it is quite simple to identify the final stages of cancer as it is when the white blood cells have destroyed almost all red blood cells at the region. the tumor spreads to other parts of the body and starts affecting major systems in the body. a terrible weight loss, loss of appetite. the cancer cells will be at a size of a papaya.

Answer 3

1.the enzyme is responsible to control the cell division so that the cell won't over divided,which causes cancer.
2.the enzyme is coded by DNA and produced by RNA (for extra information go to wikipedia and check about it's function),then they are transport to target cell by vesicles.
3.UV radiation,carcinogenic subtances or isotope that produces harmful radiation(gamma ray).
4.cancer or tumour.
5.foods,polluted air and waters may causes cancer,there are peoples saying that the depletion of ozone layer in stratosphere caused by CFC(chlorofluorocarbon) also responsible for this phenomenon.
6.it is answered,the final stage of cancer is when the cancer cell is flowing in the bloodstream.

Answer 4

look in the index under cells or cell cycle