If a chromosome fragment breaks off and then reattached to the original chromosome, but in the reverse direction, the resultant chromosomal aberration is called:

An inversion

Explanation:

An inversion occurs when a chromosome breaks in two places; the resulting piece of DNA is reversed and re-inserted into the chromosome. Genetic material may or may not be lost as a result of the chromosome breaks.

as in mitosis, dna replication occurs during interphase.   in meiosis, it occurs specifically in s phase of interphase 1.