Define nondisjunction, euploidy, aneuploidy, monosomy and trisomy.
Nondisjunction: Nondisjunction is a genetic error that occurs during cell division in which chromosomes fail to separate properly. This can result in an unequal distribution of chromosomes in the daughter cells, leading to an abnormal number of chromosomes in the offspring.
Euploidy: Euploidy refers to the normal, balanced set of chromosomes in an organism's cells. For humans, euploidy usually means having 46 chromosomes, with 23 pairs of chromosomes.
Aneuploidy: Aneuploidy is a type of chromosomal abnormality in which there is an abnormal number of chromosomes in a cell. This can result from nondisjunction during cell division, leading to an extra chromosome (trisomy) or a missing chromosome (monosomy).
Monosomy: Monosomy is a type of aneuploidy in which a cell has only one copy of a particular chromosome, instead of the usual two copies. Monosomy of certain chromosomes is often incompatible with life and can result in developmental abnormalities and birth defects.
Trisomy: Trisomy is a type of aneuploidy in which a cell has an extra copy of a particular chromosome, resulting in three copies instead of the usual two. The most well-known trisomy in humans is Trisomy 21, also known as Down syndrome, which results from an extra copy of chromosome 21. Other examples include Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome).