a)A met⁺ strain of Neurospora was treated with a mutagen to create met^- mutants.The mutants were reverted to met⁺ with HA (hydroxylamine),which causes GC to AT transitions.What was the original mutation on the molecular level?
b)Two of the revertants showed odd results when crossed with a wild-type met⁺ strain.
$\begin{array} { l l } \text { Cross } & \text { Progeny } \\\text { met } ^ { + } \text {revertant A } \times m et ^ { + } \text {wild type } & 8 8 \% \text { met }^+ \\& 12 \% \text { met }^-\end{array}$ $\begin{array}{ll}\text { met }^{+} \text {revertant B } \times \text { met }^{+} \text {wild type }& 93 \% \text { met }^{+}\\&7\% \text { met }^-\end{array}$
Explain how these results occurred and why the above numbers of offspring were obtained.

Question

a)A met⁺ strain of Neurospora was treated with a mutagen to create met^- mutants.The mutants were reverted to met⁺ with HA (hydroxylamine),which causes GC to AT transitions.What was the original mutation on the molecular level?
b)Two of the revertants showed odd results when crossed with a wild-type met⁺ strain.

\begin{array} { l l } \text { Cross } & \text { Progeny } \\\text { met } ^ { + } \text {revertant A } \times m et ^ { + } \text {wild type } & 8 8 \% \text { met }^+ \\& 12 \% \text { met }^-\end{array}

\begin{array}{ll}\text { met }^{+} \text {revertant B } \times \text { met }^{+} \text {wild type }& 93 \% \text { met }^{+}\\&7\% \text { met }^-\end{array}

Explain how these results occurred and why the above numbers of offspring were obtained.

Quizplus · Accepted Answer

The Answer of a)A met⁺ strain of Neurospora was treated with a mutagen to create met^- mutants.The mutants were reverted to met⁺ with HA (hydroxylamine),which causes GC to AT transitions.What was the original mutation on the molecular level? b)Two of the revertants showed odd results when crossed with a wild-type met⁺ strain. $$\begin{array} { l l } \text { Cross } & \text { Progeny } \ \text { met } ^ { + } \text {revertant A } \times m et ^ { + } \text {wild type } & 8 8 \% \text { met }^+ \ & 12 \% \text { met }^- \end{array}$$ $\begin{array}{ll} \text { met }^{+} \text {revertant B } \times \text { met }^{+} \text {wild type }& 93 \% \text { met }^{+}\ &7\% \text { met }^- \end{array}$ Explain how these results occurred and why the above numbers of offspring were obtained.

A)A Met+ Strain of Neurospora Was Treated with a Mutagen

A)A Met⁺ Strain of Neurospora Was Treated with a Mutagen