8.2.3 Cancer: When Mitosis Goes Unchecked Flashcards
1
Q
cancer
A
- are cells that have an unregulated cell cycle. Cancer cells are immortal, do not need to be anchored in order
to grow, and do not exhibit density-dependent inhibition
2
Q
oncogene
A
- a cancer-causing gene found in viruses and in genomes of organisms.
3
Q
proto-oncogene
A
- a regularly occurring gene that is involved in cell cycle regulation and that has the potential to become
an oncogene if altered. A proto-oncogene can be switched to an oncogene by several mechanisms including the transposition of the gene to a different promoter, the amplification of a gene, and gene mutation - can be switched to oncogenes by a variety
of methods:
· If the proto-oncogene is moved to a more active promoter by transposition, there could be a higher production of regulatory proteins that could, in turn, allow the cell to divide out of control.
· Gene amplification causes more gene expression. If there is an excess of a regulatory protein, then the cell cycle could continue out of control.
· If the protein product of a mutated proto-oncogene gene is changed in such a way that it is unable to be
degraded, then the cell cycle could continue.
4
Q
Peyton Rous
A
- In 1911 Peyton Rous discovered that viruses could cause cancer. Viruses are able to inject their genetic material into a host cell. Some viruses multiply by causing the host cell to replicate uncontrollably.
5
Q
A major difference between cancer cells and normal cells is that
A
- cancer cells will not stop growing when they are crowded
6
Q
What is metastasis?
A
- The migration of cancer cells from their origin
7
Q
What is the difference between an oncogene and a proto-oncogene?
A
- An oncogene is a cancer-causing gene, while a proto-oncogene is a normally occurring gene that does not cause cancer but could
8
Q
Which of the following statements is false?
A
- Proto-oncogenes result from viral infections
9
Q
A / An __________ mutates and becomes a / an __________, which causes cancer.
A
- proto-oncogene; oncogene