Chromosome complement with $2 n-1$ is called

When a change in the chromosome number does not involve entire sets of chromosome and restrict to only a few of chromosome, the situation is called aneuploidy. Aneuploidy may be of following types (a) Monosomic $(2 n-1)$ (b) Trisomic $(2 n+1)$ (c) Nullisomic $(2 n-2)$ (d) Tetrasomic $(2 n+2)$ (e) Double momosomic $(2 n-1-1)$ (f) Double trisomic $(2 n+1+1)$