Why yeast cells are interesting, from the Howard Hughes Medical Institute:
Key findings about human genes have come from studying the humble, blob-like cells of baker's or brewer's yeast, which one researcher calls, shockingly, our relatives. In 1996, yeast became the first eukaryote (an organism whose genetic material is enclosed in a cell nucleus) to have its entire genome sequenced. Ever since, it has remained at the forefront of research on genetics. Almost everything we know about the cell-division cycle, for instance, comes from experiments with yeast, and many new methods of analyzing genes were first tried out in yeast.Some more resources on yeast cells:
The University of Sidney in Australia's website on fungi.