3.1 Quiz Review
In some types of colon cancer, stem cells have a mutation in the APC gene. What happens if the APC gene is mutated?
If the APC gene is mutated people have familial adenomatous polyposis or attenuated FAP
What is the G0 phase of the cell cycle?
a resting, or nondividing, stage.
mitosis
cell division that results in two identical daughter cells
Oncogenes
genes that cause cancer by blocking the normal controls on cell reproduction
Cells divide, differentiate, or die. What is differentiation?
Differentiation is a process when cells stop dividing to specialize in structure and function.
Apoptosis
Apoptosis is a process that eliminates unnecessary cells during development and removes unhealthy or damaged cells in the mature organism. programmed cell death, can be normal or not normal
How do mutated tumor suppressor genes affect the cell cycle?
a. To cause cancer, tumor suppressor genes require 2 allele(s) to be mutated and therefore are considered recessive . The mutation results in a loss of function.
Interphase
period of the cell cycle between cell divisions
Can cells leave G0
Yes, such as in the injury of the liver.
Tumor Supressor Genes
-prevent uncontrolled cell growth -repair damaged DNA -control cell anchorage (absent in cancers)`
Cancer
A disease in which somebody cells grow and divide uncontrollably, damaging the parts of the body around them.
What type of mutations might occur that cause proto-oncogenes to become oncogenes?
A mutation that encodes for a protein with abnormal activity or a point mutation.
1. A patient enters a hospital after hitting her head in a car accident. She is diagnosed with a fractured skull but has other symptoms that show she is suffering from brain damage. What technology should be used to confirm this diagnosis?
An MRI scan should be done because the brain is soft tissue and this testing doesn't have radiation. Radiation can increase the chances of getting cancer.
What are cell cycle regulators?
Cell cycle regulators are molecular signals that may stimulate or half cell division,instruct cells to differentiate, or initiate cell death.
Cancer is the result of an improperly regulated cell cycle. Describe two reasons why cells can form tumors.
Cells can form tumors because of too much cell division or too little cell division.
three phases of interphase
G1: DNA double helix unwinds exposing the bases, mRNA copies it and leaves S: Two strands of identical DNA form G2: Protein synthesis and cell growth
What happens if cell cycle regulators don't function properly?
If cell cycle regulators don't function properly an organism may end up with too few or too many cells.
2. Come up with a situation where it would be inappropriate to use an MRI scan as a diagnostic tool.
If you have a pacemaker in your body it is inappropriate and a huge danger to get a MRI scan because an MRI machine uses powerful magnets that can attract metal in your body.
Why is cell division important for both unicellular and multicellular organisms?
It is important for both unicellular and multicellular organisms because these organisms need cell division to grow and to replace damaged or dead cells.
How does p53 prevent cancer cells from forming?
It regulates the cell cycle and produces a protein called p21 that has an impact on the cell cycle. It also functions as a tumor suppressor gene. CDK which is an enzyme checks the DNA for mutations in the DNA.
Why does cell division remain important to an adult organism even after it is fully developed?
It remains important to an adult organism even after it is fully developed because most of our cells are continuously renewed,
Stimulatory proteins are encoded by...
Proto-oncogenes. (Ex. Growth factors)
What is the difference between normal cell division and cancer cell division?
The difference between normal cell division and cancer cell division is in normal cell division the cell follows the signals on when it is to start and stop dividing. When it is required to divide it will enter mitosis and if it is required to stop it well enter apoptosis. In cancer cell division there are no signals and the cells continues to divide in an uncontrolled manner.
3. Explain why a combination of X-rays, CT scans, bone scans and MRI scans is used when diagnosing bone cancer.
The different tests produce different images of the inside of the body. Certain tests have the ability to produce things that others do not. It also provides images of the entire body when multiple scans and X-rays are done making it a lot more accurate and likely that something will be detected if there is something that is present.
Which factors determine whether a cell enters G0?
The type of cell and the resources available.
How does cancer spread or metastasize?
They leave the tumor and enter the bloodstream. This can carry them to another part of their body. Cancer cells will try to divide and produce another tumor.
In general, what is the purpose of a checkpoint in the cell cycle?
To make sure there are no mutations and everything is going well.
Inhibitory proteins are encoded by...
Tumor suppressor genes. (Ex. Retinoblastoma protein {Rb})