Final answer:
A euploid organism has a chromosome count that is a precise multiple of the chromosome set, such as humans with 46 chromosomes (diploid) in somatic cells and 23 chromosomes (haploid) in gametes.
Step-by-step explanation:
A euploid organism is one with a chromosome number that is an exact multiple of a chromosome set. Euploidy means the cells have the appropriate number of chromosomes for their species; in humans, this condition is referred to as having 46 chromosomes in body cells (22 pairs of autosomal chromosomes and a pair of sex chromosomes), a state known as diploid (2n). The letter 'n' is used to represent a single set of chromosomes; hence, diploid organisms are designated as 2n.
Conversely, haploid cells, such as human gametes (sperm or eggs), contain a single set of 23 chromosomes and are designated 1n, or haploid. Polyploidy is a condition where an organism has more than two sets of chromosomes. This is common in plants, where polyploid individuals tend to be larger and more robust than those with the standard diploid number.