[Seetal]

A normal peptide has 100 amino acids. Following mutation, it has only 20; 1–10 are the same as the normal peptide; 11–20 differ from the normal peptide. Which of the following mutations occurred?

(A) Nucleotide deletion in the codon for amino acid 11 (codon 11)
(B) Nucleotide deletion in codon 20
(C) Nucleotide deletion in the intervening sequence
(D) Nucleotide substitution in codon 11
(E) Nucleotide substitution in codon 20

 

[khanar]

So difficult

It seems that nobody dare to answer this question

 

[just_md]

Not sure, but may be option A.

 

[doctorsrock]

Answer

the correct answer is A.

 

[HouseWannabe]

Alrite this is my take on it:

This is a frame shift mutation that resulted at a stop codon at position 20. Therefore, it can't be a substitution and has to be a deletion so that leaves A, B, or C

B could result in a shortened chain but the change would be after position 20.

C would result result in a misense mutation and not necessarly a truncated protein as much as a non-functional one.

So the only thing left is A would would cause the frame shift mentioned above.

 

[Seetal]

haha

yes the answer is A. unfortunately i dont have the explanation for it. so if anyone could explain y pls??

 

[khanar]

The explanation is there

yes the answer is A. unfortunately i dont have the explanation for it. so if anyone could explain y pls??

Did you read housewannabe answer! He explained it very nice.