Molecular Basis Of Inheritance Question 122
Question: Which enzymes will be produced in a cell in which there is a nonsense mutation in the lac Y gene?
Options:
A) Lactose Permease
B) Transacetylase
C) Lactose permease and transcetylase
D) $ \beta $ -galactosidase
Show Answer
Answer:
Correct Answer: D
Solution:
[d] A non-sense mutation is the one which stops polypeptide synthesis due to formation of a terminating or non-sense codon.
e.g.
ATT(UAA), ATC (UAG), ACT(UGA).
The lactose or lac operon of Esherichia coli contains structural genes (z, y, a).
If Y codes for termination of polypeptide chain then only the product of ‘z’ gene transcribe to form $ \beta $ galactosidase.