The method used to identify the number of sets of

chromosomes within a

cell or

organism (i.e. its

ploidy). Each set is designated "n" so one set is n is haploid, two sets is 2n is

diploid, three sets is 3n is

triploid, four sets is 4n is

tetraploid, etc. Also, 2n+1 is known as

trisomy (i.e. two full sets plus a third copy of one of the chromosomes).

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.