Definition: (PLOY-dee) The number of single sets of chromosomes in a cell or an organism.
Haploid is having the same number of sets of chromosomes as a germ cell or half as many as a somatic cell. See illustration below.
Diploid is having two sets or a pair of chromosomes, as normally found in the somatic cell of higher organisms. A diploid cell has one chromosome from each parent. See illustration below.
Triploid is having three times the haploid number of chromosomes in the cell nucleus and would be abnormal in humans.
Tetraploid is having four times the haploid number of chromosomes in the cell nucleus.
Aneuploid is a chromosome number that is not an exact multiple of the normal diploid number, with either fewer or more than the normal number of chromosome in the cell. In humans, an aneuploid cell would be considered abnormal. A triploid cell would be an example of aneuploidy in humans.