Experiments: looking at yeast cells; isolation and characterization of auxotrophic, temperature-sensitive and UV-sensitive mutants; meiotic mapping; mitotic recombination and random spore analysis; transformation of yeast; synthetic lethal mutants; gene replacement; isolation of ras2 suppressors; manipulating cell types; isolating mutants by insertional mutagenesis; two-hybrid protein interaction method. Techniques and protocols: high-efficiency transformation of yeast; "Lazy Bones" plasmid transformation of yeast colonies; yeast DNA isolations; yeast DNA miniprep (40 ml); yeast DNA miniprep (5 ml); a ten-minute DNA preparation from yeast; yeast genomic DNA - glass bead preparation; yeast protein extracts; yeast RNA isolation; hydroxylamine mutagenesis of plasmid DNA; assay of beta-galactosidase in yeast; plate assay for carboxypeptidase Y; random spore analysis; yeast vital stains; yeast immunofluorescence; actin staining in fixed cells; PCR protocol for PCR-mediated gene disruption; yeast colony PCR protocol; measuring yeast cell density by spectrophotometry; cell synchrony; chromatin immunoprecipitation; flow cytometry of yeast DNA; logarithmic growth; EMS mutagenesis; tetrad dissection; making a tetrad dissection needle; picking zygotes; determining plating efficiency. Appendices: media; stock preservation; yeast genetic and physical maps; templates for making streak plates; electrophoretic karyotypes of strains for southern blot mapping; strains; counting yeast cells with a standard hemocytometer chamber; tetrad scoring sheet; trademarks; suppliers.