Which of the following statements about araC^- and lacI^- mutants are true,with reference their respective operons? Assume both of these are loss of function mutations.

Question

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The ara operon is responsible for metabolism of arabinose, while the lac operon is responsible for metabolism of lactose. Both of these operons have regulatory genes (araC and lacI, respectively) that control the expression of the operon. Loss of function mutations in these regulatory genes can affect transcription of the operon. In the case of the araC^- mutant, the mutation is in the araC gene, which means that the regulatory protein is non-functional. This would result in non-inducible expression of the ara operon, meaning transcription would not occur. In contrast, the lacI^- mutant has a mutation in the lacI gene, but this would not necessarily result in loss of inducibility of the lac operon. The lacI protein is a repressor of the lac operon, and loss of function mutations in the lacI gene can lead to constitutive expression of the operon (meaning transcription occurs regardless of whether lactose is present or not). Therefore, it is possible that this mutant still allows transcription, although it may not be inducible. Overall, the correct statement is that araC^- mutants do not allow transcription, but lacI^- mutants may still allow transcription (although it may not be inducible). Therefore, choice A is the best answer.

Which of the Following Statements About araC- and lacI- Mutants

Which of the Following Statements About araC^- and lacI^- Mutants