Question

In lac, operon if y gene undergoes in silent mutation then what changes we observe during expression of structural gene
(A) no any enzyme synthesis will occur
(B) permease enzyme will synthesise only
(C) only bela galactosidase will synthesise
(D) no changes occur in enzyme synthesis by structural gene​

Answer 1

Explanation:

Nonsense mutation is a type of mutation in which sense codon is changed to a chain-terminating codon. The lac genes encoding enzymes are lac Z, lac Y, and lac A. Transcription of lac Z gene occurs before transcription of lac Y & lac A. A nonsense mutation in the lac Y gene will produce nonfunctional permease. A stop codon will be introduced in the sequence after lac Z gene. Since only β galactosidase enzyme is produced and permease and transacetylase enzymes are not produced, lactose is not transported into the cell.

Thus, the correct answer is option A.

Answer 2

I don't know it's answer