Answer:
Deletion
Step-by-step explanation:
A mutation refers to a change in the DNA sequence. This means that the original sequence of bases in the DNA has been altered permanently.
There are three types of DNA mutations; base substitutions, deletions and insertions.
In the particular case of this question, the original is TTCGATA while the copy is TTGATA. If you look closely at the two, you will notice that the C has been omitted. This is an example of deletion.