Principle Of Inheritance And Variation Question 481
Question: Assertion : Repression occurs at transcription level. Reason : When repressor binds to the operator, transcription occurs.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: C
Solution:
The process of ?turning off? the expression of set of genes is called repression.
It occurs at the transcription level.
The operator is always located continuous to the structural gene or genes whose expression it regulates.
When the repressor is bound to the operator, transcription of the structural genes cannot occur, because the binding of the repressor to the operator sterically prevents RNA polymerase from binding at the promoter site.
The operator is usually located between the promoter and the structural genes.
BETA
