Question

A small stretch of DNA strand that codes for a polypeptide is shown below:

3'--- --- --- --- CAT CAT AGA TGA AAC--- --- --- --- 5'

(a)  Which type of mutation could have occurred in each type resulting in the following mistakes during replication of the above original sequence? 

(i)  3`… … … …CAT CAT AGA TGA ATC… … …5` 

(ii)  3`… … … …CAT ATA GAT GAA AC… … … 5`

(b)  How many amino acids will be translated from each of the above strands (i) and (ii)?

Answer 1

(a) i.  point mutation/ single base substitution

ii.  point mutation/ single base deletion

(b)  i.  4 aminoacids

ii.   4 aminoacids