Assume that a series of compounds has been discovered in Neurospora.Compounds A-F appear to be members of an enzyme pathway.Several mutations have been identified and each of strains 1-4 contains a single mutation.Shown below are five possible pathways.Choose the pathway that best fits the data presented.[Growth in minimal media with supplements is shown by (+),no growth is shown by (o).] $\begin{array}{|c|c|c|c|c|c|c|}\hline\text { strain }&A&B&C&D&E&F\
\hline 1& \text { o } & \text { o } & \text { o } &+ & + & + \
\hline 2& \text { o } & \text { o } & \text { o } &\text { o } & + & + \
\hline 3& \mathrm{o} & \text { o } & \text { o } & \text { o } & + &\text { o } \
\hline 4& \text { o } &\text { o } & + & + & + & + \
\hline
\end{array}$
A) A ? B ? C ? D ? E ? F
B) A ? B ? C ? F ? D ? E
C) F ? B ? C ? D ? A ? E
D) A ? B ? C ? D ? F ? E
E) A ? B ? F ? E ? C ? D

Question

Quizplus · Accepted Answer

The correct pathway is A ? B ? C ? D ? F ? E. This is because strain 1 is unable to grow on minimal media with supplements A, B, or C, but can grow on minimal media with supplements D, E, or F. This indicates that strain 1 has a mutation in the gene that encodes the enzyme that catalyzes the conversion of A to B. Strain 2 is unable to grow on minimal media with supplements A, B, or C, but can grow on minimal media with supplements D or E. This indicates that strain 2 has a mutation in the gene that encodes the enzyme that catalyzes the conversion of C to D. Strain 3 is unable to grow on minimal media with supplements A, B, or C, but can grow on minimal media with supplement E. This indicates that strain 3 has a mutation in the gene that encodes the enzyme that catalyzes the conversion of D to E. Strain 4 is unable to grow on minimal media with supplements A or B, but can grow on minimal media with supplements C, D, E, or F. This indicates that strain 4 has a mutation in the gene that encodes the enzyme that catalyzes the conversion of B to C.

Assume That a Series of Compounds Has Been Discovered in Neurospora.Compounds