Baker's yeast is a single-celled eukaryotic organism that spends part of its life-cycle as a haploid and part as a diploid. In either case, the haploid or diploid cells can grow independently, which is useful for genetic analysis. Due to its ability to survive as both a diploid and a haploid, aneuploidy is very well tolerated in yeast.
Aneuploidy is defined as having an abnormal number of chromosomes, such as a trisomy or a monosomy. Diploid yeast can be induced to sporulate, causing the diploid to produce four haploid spores.
If there were a non-disjunction of a single chromosome during meiosis II, what pattern of growth would you expect to see of the four spores?