Question

10. The wildtype DNA has the following sequence:              

                                                          ACGATTACGAA

It has undergone mutation and it now has the sequence (mutation is in BOLD):

                                                        ACGACGCACGAA

answer questions a-e below in the textbox under this question

a. what is this type of mutation called?

b. this type of mutation results in a protein that is shorter than usual. True or False

c. what mutagen caused this mutation?

d. what does this mutagen do to the DNA

e. can this mutation be repaired- just answer yes (name the mechanism if you answer yes) or no.

Answer 1

Wild type: DNA:    3'- ACG ATT ACG AA - 5'

Wild Type mRNA: 5'- UGC UAA UGC UU - 3'

Wild type aminoacid sequence-: NH3+ - Cys-STOP- COO-

Mutant type DNA:   3' -ACG ACG CAC GAA - 5'

Mutant type mRNA: 5' - UGC UGC GUG CUU - 3'

Mutant type aminoacid sequence: NH3+ - Cys-Cys-Val-Leu - COO-

a. This type of mutation is called Frameshift mutation which is caused by indels (insertions or deletions) in the DNA sequence wherein, it changes and shifts the way it is read.

b. FALSE. The mutation results in a protein longer than the wild type.

c. Base Analog mutagen might be causing this mutation.

d. These mutagens (base analog) are basically chemicals that exactly mimic the bases by having a very similar structure to the normal bases and they mimic the normall bases to an extent where they will be incorporated into DNA in place of one of our regular bases this results in increase in rate of mutation.

e. Yes, Frameshift mutations can be revertible by using frameshift mutagens.Reverse mutations can occur which can change the sequence of mutant type into the wild type and another possibility is by usage of suppressor mutations.