Question

multiple - choice question
a deletion mutation occurs when...
an extra base is added in.
a base is taken out.
a base is replaced with the wrong one.
rewatch

Explanation:

In genetics, a deletion mutation is defined as the removal of one or more nucleotides (bases) from the DNA sequence. Adding an extra base is an insertion mutation, and replacing a base is a substitution mutation.

Answer:

B. a base is taken out.