Final answer:
A euploid organism has a chromosome number that is an exact multiple of the set number for the species. Humans, for example, are generally euploid with 46 (2n) chromosomes in somatic cells and 23 (n) chromosomes in gametes. Polyploidy refers to more than two sets of chromosomes, often found in plants.
Step-by-step explanation:
A euploid organism is one with a chromosome number that is an exact multiple of a chromosome set. Euploidy designates the condition where an individual has chromosomes in complete sets. For instance, humans are generally euploid with each somatic cell containing 46 chromosomes, a condition known as diploid (2n), with homologous chromosomes forming matched pairs.
Gametes, or sex cells, have a haploid (n) state with 23 chromosomes each. Polyploidy is a situation where an organism has more than the normal diploid number of chromosome sets, which is more common in plants than in animals.