ANATOMY

Detailed explanation-1: -A pathogen is defined as an organism causing disease to its host, with the severity of the disease symptoms referred to as virulence. Pathogens are taxonomically widely diverse and comprise viruses and bacteria as well as unicellular and multicellular eukaryotes.

Detailed explanation-2: -Pathogens include viruses, bacteria, fungi, and parasites that invade the body and can cause health issues. Anthrax, HIV, Epstein-Barr virus, and the Zika virus, among many others are examples of pathogens that cause serious diseases.

Detailed explanation-3: -Among the bacterial pathogens, Escherichia coli, Salmonella, Shigella, Campylobacter, Salmonella typhi, Vibrio cholerae, and Pseudomonas are mostly encountered in the environment.