You Have Made a Collection of Mutant Fruit Flies That

question 58

Essay

You have made a collection of mutant fruit flies that are defective in various aspects of DNA repair.You test each mutant for its hypersensitivity to three DNA-damaging agents: sunlight, nitrous acid (which causes deamination of cytosine), and formic acid (which causes depurination).The results are summarized in Table 6-61, where a "yes" indicates that the mutant is more sensitive than a normal fly, and blanks indicate normal sensitivity. $\begin{array}{ll}&\text { sunlight \quad nitrous acid \quad formic acid }\\\begin{array}{rl}\text { Dracula}\\\text { Faust}\\\text { Mole}\\\text { Mr Self-destruct}\\\text {Marguerite }\end{array}&\begin{array}{|c|c|c|}\hline \text { yes }\quad\quad & & \\\hline & \text { yes } & \\\hline \text { yes } & & \\\hline \text { yes } & \text { yes }\quad\quad\quad & \text { yes }\quad\quad\quad \\\hline & & \text { yes } \\\hline\end{array}\end{array}$

Table 6-61
A.Which mutant is most likely to be defective in the DNA repair polymerase? Why?
B.What aspect of repair is most likely to be affected in the other mutants?

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Definitions:

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