Triploidy is a type of chromosomal abnormality where offspring are born with an extra set (i.e 3rd set) of chromosomes in their cells. One defining character of triploids is their sterility. This is due pairing in meiosis. In a triploid, there are two possible pairing mechanisms: one chromosome can pair with one partner on one part and another partner with the remaining length, forming a trivalent; and one forming a bivalent and an unpaired chromosome (univalent).
Why are triploid organisms usually sterile?
A. Three copies of each gene will cause too much expression.
B. The vast majority of meiotic products will be aneuploid.
C. Meiosis is impossible with more than two homologous chromosome copies.
D. Many gametes will be missing one or more chromosomes.