A couple undergoing in vitro fertilization found out that their egg and sperm were first fertilized in a petri dish, and the resulting embryo was planted into the uterus for further development. Prior to placement into the uterus, the embryo was screened for abnormalities. The image shows the karyotype of the embryo. What type of issue would the doctor be able to identify from the karyotype?

A series of chromosome pairs. Many of the chromosome pairs do not look like they properly separated.

mutations in the DNA
improper crossing-over
errors during fertilization
chromosomal nondisjunction