👉 The term "exobasidiales" is a biological term that refers to organisms characterized by their presence of a single, or only one, pair of chromosomes. These are called exomeric chromosomes and are typically found in eukaryotic cells. The presence of two sets of chromosomes in an organism's genome can cause genetic disorders such as Down syndrome, which results from the loss of two sets of chromosomes. Exobasidiales are also known as trisomy 21 or