In a study, researchers replaced the natural promoter of a gene with a synthetic promoter that contains a point mutation in the TATA box that prevents binding of the TATA-binding protein (TBP). The following outcomes would most likely result from this modification.

A. An mRNA will be generated with an alternate reading frame.
B. The mRNA will be transcribed by RNA polymerase I instead of RNA polymerase II.
C. Transcription may occur with a reduced efficiency.
D. Transcription may occur but will always result in the formation of a non-functional mRNA.

Which one of the following options represents the combination of all INCORRECT statements?

Correct option is B

EXPLANATION-

A. An mRNA will be generated with an alternate reading frame.
This is incorrect – The reading frame is determined by the coding sequence and not by the TATA box or promoter mutations.

B. The mRNA will be transcribed by RNA polymerase I instead of RNA polymerase II.
This is incorrect– RNA polymerase I transcribes rRNA, not mRNA. mRNA is still transcribed by RNA polymerase II (though possibly less efficiently).

C. Transcription may occur with a reduced efficiency.
This is correct– This is likely. TBP is crucial for transcription initiation; its absence may reduce transcription efficiency.

D. Transcription may occur but will always result in the formation of a non-functional mRNA.
This is incorrect – Even if transcription is affected, if it does occur, the mRNA may still be functional. It’s not guaranteed to be non-functional.

Incorrect statements: A, B, and D
So, the correct option is (b)  A, B and D