Fungi. A fungus (singular) is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms (Figure 1). Fungi are classified as a kingdom that is separate from plants, animals, and bacteria.One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose.he discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants. Pathogenic fungi are fungi that cause disease in humans or other organisms.
Erectile Dysfunction Causes and Symptoms. There are many causes of erectile dysfunction (impotence) and some include: 1  blood vessel diseases (such as peripheral vascular disease and others), 2  systemic disease, 3  hormonal imbalance, and. 4  medications (such as blood pressure and heart medications).
Most erectile dysfunction is caused by a physical condition that affects the nerves or blood vessels responsible for erections. Causes include diabetes, vascular disease, multiple sclerosis, Parkinsonâs disease, surgery or radiation therapy for prostate cancer, or the side effects of medication. Psychological causes include anxiety, depression, or stress.