Chromosomal rearrangements can occur after chromosomes break. Which of the following statements are most accurate with respect to alterations in chromosome structure?
A. Chromosomal rearrangements are more likely to occur in mammals than in other vertebrates.
B. Translocations and inversions are not deleterious because no genes are lost in the organism.
C. Chromosomal rearrangements are more likely to occur during mitosis than during meiosis.
D. An individual that is homozygous for a deletion of a certain gene is likely to be more damaged than is one that is homozygous for a duplication of that same gene because loss of a function can be lethal.

Translocations and inversions can be extremely deleterious, for example, if the break point is within a gene, that gene would be dysfunctional, or a new harmful fusion gene could be created

Rearrangements are not more likely to occur in mitosis than meiosis

A homozygous deletion for a gene means none of that gene product will be made. If this product is important, this could cause problems for that individual. An individual that is homozygous for a duplication still has a copy of the gene, so while they may face some problems owing to the overexpression of the gene, it is more likely that not having the gene at all will be more problematic (depending on the gene of course!)