Ans. Ascomycetes, also known as sac fungi, include a diverse group of fungi that are characterized by the presence of ascocarps, specialized structures that produce sexual spores called ascospores. Examples of Ascomycetes include yeast (Saccharomyces cerevisiae), truffles (Tuber spp.), and many plant pathogens such as powdery mildews (Erysiphales spp.) and apple scab (Venturia inaequalis).