BIOL 200 Lecture Notes - Rad51, Transcription Factor Ii H, Guanine

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ceruleanprairie-dog589

6 Apr 2012

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Document Summary

Over the course of evolution, errors in dna replication can introduce permanent, transmissible changes into a daughter cell of organism. This is known as a mutation to dna. This causes the encoding for different mrna molecules after translation, and, eventually, different amino acids coded during translation. Mutagens, on the other hand, are chemical compounds, ultraviolet radiation, or ionizing radiation (x-rays and atomic particles) which can increase the frequency of mutation. A carcinogen is an agent that causes cancer. Carcinogens can introduce the following changes into a normal cell: There are multiple methods of dna repair through which the cell can prevent the occurrence of mutations. Each of the mechanisms can take place at different times after transcription in order to maximize effectiveness. Note that we will use a eukaryotic model to explain dna repair. E. coli dna polymerase can introduce 1 error in every 10,000 nucleotides incorporated into new polynucleotide strands.

Related Questions

1. The RAS proteinacquires a mutation that prevents release of GTP. Which of thefollowing characteristics are these cells likely toacquire?

A. Self-Sufficiency in growth signals
B. Insensitivity to anti-growth signals
C. Metastasis

2. Which of the following genes would you suspect to bea tumor supressor?
A. MSH2
B. CDK2
C. c-myc

3. A gene that is involved in a normal cellular processesbut when mutated contribute to cancer developmentis:
A. a proto-oncogene
B. a housekeeping gene

4. When a person carries a mutation in a tumor suppressorgene on one-chromosome and subsequently loses function of theirwildtype tumor suppressor allele, this describes:
A. gene conversion to an oncogene
B. loss of heterozygosity
C. haploinsufficiency

5. The mechanism by which alterations in DNA methylationcould promote carcinogenesis is:
A. by lengthening telomeres
B. by interacting with reactive oxygen species and thereforebecoming a potent mutagen
C. by either repressing or enhacing gene expression

6. When anaylzing a cell you find that it has aninactivating mutation in p53 and a mutation in the VEGF receptorthat makes activation independent of ligand binding. Which of thefollowing hallmarks would you expect the cell toexhibit?
I. self-sufficiency in growth
II. insensitivit to anti-growith signals
III. limitless replicative potential
IV. evading apoptosis
V. sustained angiogenesis

A. IV and V only
B. II, III, VI
C. I and III only