IMMUNOLOGY

Detailed explanation-1: -Pathogenic organisms are of five main types: viruses, bacteria, fungi, protozoa, and worms. Some common pathogens in each group are listed in the column on the right.

Detailed explanation-2: -Infectious diseases are caused by pathogens, which include bacteria, fungi, protozoa, worms, viruses, and even infectious proteins called prions.

Detailed explanation-3: -There are different types of pathogens, but we’re going to focus on the four most common types: viruses, bacteria, fungi, and parasites.