Exam 12: Gene Mutation, DNA Repair, and Homologous Recombination

________ are structures that have the same composition and general arrangement but a slight difference in bonding and placement of a hydrogen.

Gene conversion can be observed in fungi by identifying aberrant ratios in the ascus.Which of the following represent possible aberrant ratios caused when there is no mismatch repair of base-pair mistakes in the heteroduplex region?

You have developed a new drug and have been asked to test the drug's mutagenicity before putting it on the market.Which test could you use to determine your compound's mutagenic potential?

Which enzyme is the product of the phr gene in E.coli?

Which type of mutagen has a structure similar to one of the DNA nucleotides and therefore can work its way into DNA,where it pairs with a nucleotide?

What two types of spontaneous damage to individual nucleotides are associated with subsequent mutation?

Which of the adenines in the following sequence could you mutate to create a missense transition mutation? 5′-ATG GGA TGG CAC CTG-3′

What process,which is responsible for many trinucleotide repeat disorders,alters the number of DNA repeats?

What term describes a gene or region of a genome where mutations occur much more often than average?

You would like to induce a transversion mutation into a sequence of DNA.Which type of chemical mutagen would give you the best chance of inducing the correct mutation without causing transition mutations as well?

Agents generating mutation-inducing DNA damage are collectively referred to as ________.

The Ames test is designed to identify the rate of ________ that restore the ability of bacteria to synthesize their own histidine,thus eliminating the need for histidine supplementation of the growth medium.

You accidentally exposed your cell culture dish to radiation,but you are not sure of the precise wavelength of the exposure.How can you use the induced DNA damage to tell whether the radiation was UV or higher energy? What is the difference between the DNA damage caused by UV radiation compared to higher-energy radiation? Which type of damage is the most likely to be the most lethal to your cells?

You have conducted an Ames test on a given compound.Which of the following would be classified as a positive result on the Ames test?

Which type of double-stranded break repair would you expect to be used by a cell in the G₁ phase of the cell cycle?

Studies of gene mutation frequencies have shown that

You use several model organisms in your lab's research.Which of your model organisms would you expect to exhibit a higher mutation frequency: E.coli,D.melanogaster,or M.musculus?

Which pathway is affected by an inherited mutation in the ATM gene?

Localized mutations that occur at a specific or identifiable location on a gene are better known as what?

What type of mutagen would you use if you wanted to study the effect of pyrimidine dimers in causing cancer?