Question

Which one of the following statements regarding regulatory proteins is incorrect ?

• A. They can act as both activators and repressors
• B. The activators bring about a positive effect in gene regulation
• C. The repressors bring about a negative effect in gene regulation
• D. All the operon have the same regulatory protein as the activator and repressor

Answer 1

The correct option is D All the operon have the same regulatory protein as the activator and repressor

Regulatory proteins play an important role in gene regulation. They can act as both activators as well as repressors. Thus the first statement stands correct.
The activators are said to have a positive effect in gene regulation as they initiate or start the process of gene expression whereas the repressors are said to have a negative effect as they suppress the expression of a gene. Hence b and c are also correct.
However, all operons do not have the same regulatory protein as the activator and repressor. Each operon has its specific operator and repressor.