Question

In some species of bacteria that are resistant to the antibiotic tetracycline, the antibiotic molecule attaches to a repressor protein. This prevents binding of the repressor to the bacterial DNA and allows a set of genes to be transcribed. The transcription of these genes is under the control of a(n) _____.

a) Promoter
b) Operator
c) Activator
d) Inducer

Answer 1

Repressors, activators, and inducers are three types of regulatory molecules that control the expression of operons in prokaryotic cells. Repressors prevent gene transcription, activators increase gene transcription, and inducers activate or repress transcription based on cell needs and substrate availability.

Step-by-step explanation:

In prokaryotic cells, there are three types of regulatory molecules that can affect the expression of operons: repressors, activators, and inducers. Repressors are proteins that suppress transcription of a gene in response to an external stimulus, whereas activators are proteins that increase the transcription of a gene in response to an external stimulus. Inducers are small molecules that either activate or repress transcription depending on the needs of the cell and the availability of substrate.