genetics exam 3 problem sets

genetics exam 3 problem sets - Caitlin Favaloro Cbf 229...

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Caitlin Favaloro Cbf 229 Exam three problem set solutions T/Th 12:30-2 Questions for Chapter 16B Material C33. It is necessary to distinguish between the template and daughter strand because mismatch repair directly aims at repairing the daughter strand following DNA replication. The protein MutH is able to distinguish between the parent and daughter strand because the parent strand is methylated prior to DNA replication C38. The underlying genetic defect that causes XP is the cell’s inability to perform nucleotide excision repair. Because the patient cannot repair thymine dimers and base abnormalties, it has an increased sensitivity to UV light, and UV light is much more likely to create a mutation in these individuals. This results in skin pigmentation abnormalities and skin cancer as common XP symptoms. A1. DNA lesions cause damage to the template strand of DNA; however, it is not considered a mutation until DNA replication. Lesions cause mutations because the DNA polymerase cannot read the template strand correctly during DNA replication A2. Fill in the table below with your knowledge about specific mutagens, their effects, and the mechanism of their repair. Mutagen class Mutagen examples Lesion name and description Mutation(s) Direct repair Excision repair radiation ultraviolet radiation Thymine dimers are created. The single covalent bond on the two thymines cause them to move extremely close together, which prevents complimentary base pairing Either a deletion or substitution mutation will occur depending on the way the DNA polymerase synthesizes its daughter strand Photolyase separates the dimers, restoring them to their normal condition UvrABC endonucleases alkylating agents Nitrosamines and BaP It depends on where the alkyl group is added. Explain. It depends on where the alkyl group is added. Explain. Alkyltransferase removes the alkyl groups from the abnormal base, restoring it to its normal condition It depends on where the alkyl group is added. Explain. deaminating agents Nitrous acid Transition mutation <none> Glycosylases recognizes the abnormal base and cleaves the bond between it and the sugar phosphate backbone, creating an AP site. AP endonuclease then repairs the new AP site.
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Caitlin Favaloro Cbf 229 Exam three problem set solutions T/Th 12:30-2 intercalators Ethidium Bromide <none>
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Caitlin Favaloro Cbf 229 Exam three problem set solutions T/Th 12:30-2 A3. Fill in the table below with your knowledge about the three alterations that occur spontaneously in DNA, including their names, a description of their creation, the types of mutations they produce, and the mechanism for their repair. We did not discuss deamination as a spontaneous mutation.
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This note was uploaded on 05/09/2008 for the course BIO 325 taught by Professor Saxena during the Spring '08 term at University of Texas at Austin.

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genetics exam 3 problem sets - Caitlin Favaloro Cbf 229...

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