GEOLOGY

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

Detailed explanation-3: -Diseases in humans that are caused by infectious agents are known as pathogenic diseases.

Detailed explanation-4: -Infectious diseases are disorders caused by organisms-such as bacteria, viruses, fungi or parasites.