Final answer:
A pathogen is any microorganism that causes diseases, and this includes organisms like bacteria, viruses, fungi, and more. These pathogens are responsible for infectious diseases, which can be spread between individuals or contracted through environmental exposure.
Step-by-step explanation:
A pathogen is the term used for ANY disease-causing microorganism. This includes a broad range of microorganisms such as bacteria, parasites, fungi, viruses, viroids, and prions. Pathogens are responsible for infectious diseases, which are diseases caused by the direct effect of these disease-causing agents. Infectious diseases can spread from one individual to another, making some of them communicable or even contagious, whereas others may be noncommunicable and contracted through different means, like environmental exposure.
Pathogens contain pathogen-associated molecular patterns (PAMPs) that differ from molecules on host cells, allowing our immune system to detect and respond to these foreign invaders. The management of certain infectious diseases, such as HIV/AIDS, often involves the use of multiple antiviral drugs which work to control the spread of the virus within the patient's body.