So, once again, as we saw just a moment ago when we discussed the human cargotype, we saw that every single one of these chromosomes came with a pair. And this is known as dimic conditions. And so each one of these pairs describes a dilmic condition, because we have only two per pair. Sometimes, however, we can either have a trisomic individual or we can have a monosomic individual. And what that means is one of these pairs actually has an extra copy of a chromosome. So three in this particular case, or we can have one less.