What term describes an organism that can cause disease?

The term that describes an organism capable of causing disease is "pathogenic." This designation is applied to organisms, typically microorganisms such as bacteria, viruses, fungi, and parasites, that can invade host organisms and disrupt normal biological functions, leading to illness. Pathogens have specific mechanisms that allow them to evade the host's immune system and promote disease development, such as producing toxins or facilitating infection. Understanding pathogenic organisms is crucial in fields like medicine, microbiology, and infection control, as it helps in identifying and managing infectious diseases effectively.

In contrast, non-pathogenic refers to organisms that do not cause disease, often contributing positively to their environment or host. Commensal organisms live in association with a host without causing harm and may even provide beneficial effects. Mutualistic organisms engage in a relationship with their host that is beneficial for both parties. Therefore, while the other terms describe beneficial or neutral relationships with hosts, "pathogenic" specifically defines the harmful capability of an organism.