We conducted several experiments with Saccharomyces cerevisiae, in order to study the life cycle of yeast, the principles of complementation, and tetrad analysis. The life cycle of yeast can be easily studied at various stages because it reproduces through budding and exhibits predictable morphological changes in this process. Genetic complementation is the reappearance of the wild-type phenotype in offspring when there are two different homozygous recessive mutations present in the parent organisms. Complementation can be easily observed in yeast using the ADE mutations. If the ADE mutations, which inhibit adenine biosynthesis, are on separate genes, then complementation will occur. Complementation in yeast would result in the ability to produce adenine, even though neither of the haploid strains are capable of doing so. Tetrad analysis involves examining the completion of the entire yeast life cycle.