What is the difference between aneuploid organisms and euploid organisms?

Answer 1

Euploid organisms have a chromosome number that is an exact multiple of the haploid number (Euploid organisms may however, exhibit either an increase or a decrease in the chromosome number). Aneuploid organisms however, have altered genomes - they either lack chromosomes or have extra ones.

Answer 2

Aneuploid organisms have an abnormal number of chromosomes due to the gain or loss of individual chromosomes, leading to genetic imbalance. Euploid organisms have a complete set of chromosomes, with the correct number for their species, resulting in a balanced genetic composition.