APFIVE Which of the following pieces of evidence best supports the conclusion that nondisjunction can occur at either anaphase I or anaphase II, resulting in aneuploidy such as Down syndrome?
Analyses of cell division reveal that errors during both anaphase I and anaphase II can lead to gametes with abnormal numbers of chromosomes, as seen in cases where an extra copy of chromosome 21 is present.
Fluorescent in situ hybridization (FISH) consistently shows normal diploid numbers in gametes, which would rule out the occurrence of nondisjunction.
Protein assays indicating abnormal cohesin complex levels suggest potential segregation errors, yet they do not specifically pinpoint nondisjunction during anaphase I or II.
Microscopic imaging during interphase occasionally shows misaligned chromosomes, but this does not provide information about the specific stages where nondisjunction occurs.
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