Question

in e. coli cells, maltose, a type of sugar, is needed to turn on the genes that are regulated by the mal operon. this type of regulation is called (1 point)
repressor control.
operon control.
negative control.
positive control.

Explanation:

To solve this, we analyze each option:

• Repressor control: Involves a repressor protein blocking transcription, not matching as maltose activates genes.
• Operon control: Too vague; operons have specific regulation types (positive/negative).
• Negative control: Uses a repressor to stop transcription (e.g., lac operon without lactose), but here maltose activates, so not negative.
• Positive control: A molecule (like maltose here) acts as an activator to turn on gene transcription. Maltose is needed to activate the mal operon - regulated genes, so this is positive control.

Answer:

D. positive control