Nearly Half of the Pregnancies That End in Miscarriage Have

Question

Nearly half of the pregnancies that end in miscarriage have:
A) trisomy of chromosome 21
B) homozygosity for a recessive lethal allele
C) major chromosomal abnormalities
D) Klinefelter syndrome
E) Down syndrome

Accepted Answer

Nearly half of the pregnancies that end in miscarriage are due to major chromosomal abnormalities, which can include a wide range of issues such as aneuploidies, deletions, duplications, and structural rearrangements, rather than specific conditions like trisomy 21 (Down syndrome), Klinefelter syndrome, or homozygosity for a recessive lethal allele.