Final answer:
Yes, both diploid and haploid Saccharomyces cerevisiae can proliferate through mitotic cell division.
Step-by-step explanation:
Yes, both diploid and haploid Saccharomyces cerevisiae can proliferate through mitotic cell division. Saccharomyces cerevisiae, also known as brewer's yeast, primarily reproduces asexually by budding, where a daughter cell grows as an outgrowth of the parent cell and eventually separates. However, under adverse environmental conditions, haploid cells can conjugate and form a diploid zygote, which can then undergo meiosis to produce haploid spores that can germinate.