When a Structural Gene Is Under Negative Inducible Control, What

question 20

Multiple Choice

When a structural gene is under negative inducible control, what would be the result of a mutation that eliminates the repressor protein?

• A) The structural gene will be constitutively expressed due to the lack of negative inducible control.
• B) The transcription of the structural gene will not be affected, as a repressor is not required.
• C) The mutation will lead to activation of an activator upon the lack of a repressor protein, which will allow the transcription to continue.
• D) Since transcription will require a repressor protein, the transcription will be turned off.
• E) More cAMP will be produced in a cell to compensate for the lack of a repressor protein.

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Definitions:

Nucleus

Of an atom, central core area occupied by protons and neutrons. Of a eukaryotic cell, organelle with a double membrane that holds the cell’s DNA.

Nitrogenous Base

A molecule found in DNA and RNA that encodes the genetic information in cells.

DNA

A molecule comprising nucleotide chains that encode genetic information vital for the development, functioning, and reproduction of all living organisms and many viruses.

RNA

Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins.