Answer:
2) CAG - TTC - ACG mutates to CAG - TTC - ACC - ACG
Explanation:
Insertions are mutations in which extra base pairs are inserted into a new place in the DNA. The number of base pairs inserted can range from one to thousands!
In option no. 1: We see that there is not addition of a single or more than one base, but the new base sequence is different from the original sequence at three places i.e: TTA - CAC - G
In option no. 2: The insertion of three bases ACC has been made exactly after TTC, the whole sequence and arrangement of bases remain same except this insertion.
In option no. 3: The first base of the sequence T is replaced with A, and all other sequence is same. This type of mutation is called substitution in which one base is replaced by other.
In option no. 4: The last base of the sequence C is deleted, and is not present in new sequence. This type of mutation is called deletion in which a base is removed from the sequence.
Conclusion: Therefore, the best option is 2, in which whole codon is inserted in the DNA base sequence.
