申論題

5. In the 194Os, George Beadle and Edward Tatum carried out a series of experiment on the bread mold Neurospora to support for "the one gene, one enzyme" hypothesis. In this similar experiment, A, B, C are the intermediates (in that order) in a biochemicai pathway whose product is D. Z# mutants are found in five different complementation groups. Z1 mutants will grow on C or D, but not A or B. Z2 mutants will grow on B, C or D. Z3 mutants will only grow on D. Z4 mutants will grow on C or D. Finally, Z5 mutants will grow on A, B, C, or D. Please follow Beadle and Tatum's hypothesis and answer the following questions: (a) Please draw a pathway and place the five complementation groups Z# at the step in the order for synthesizing the corresponding products A, B, C, D. (5 points) (b) What does this genetic information reveal about the nature of the enzyme that carries out the conversion of B to C? (5 points)