BIO 172 EXAM 3 WITH 100%
CORRECT ANSWERS 2026
constitutive expression correct answer a gene is always
expressed
Regulated expression correct answer gene product made on
demand; expression can be
induced or repressed
What is an operon? correct answer a segment of DNA which
includes a promoter, an operator and a series of genes with
related functions.
What do repressors do? correct answer prevent transcription
by binding to a region of the DNA and preventing RNA polymerase
access to the DNA for transcription
What does polycistronic mean? correct answer more than 1
gene per mRNA; regulated by a single promoter
what is negative gene regulation? correct answer a repressor
protein binds to an operator to prevent a gene from being
expressed
CORRECT ANSWERS 2026
constitutive expression correct answer a gene is always
expressed
Regulated expression correct answer gene product made on
demand; expression can be
induced or repressed
What is an operon? correct answer a segment of DNA which
includes a promoter, an operator and a series of genes with
related functions.
What do repressors do? correct answer prevent transcription
by binding to a region of the DNA and preventing RNA polymerase
access to the DNA for transcription
What does polycistronic mean? correct answer more than 1
gene per mRNA; regulated by a single promoter
what is negative gene regulation? correct answer a repressor
protein binds to an operator to prevent a gene from being
expressed
