Which term describes a disease caused by an agent that can pass from one living thing to another?

Which term describes a disease caused by an agent that can pass from one living thing to another?

• A. Infectious disease
• B. Cancer
• C. Immune response
• D. Antibiotic

Answer: (A)

Infectious disease describes illnesses caused by pathogens—bacteria, viruses, fungi, or parasites—that can be passed from one living thing to another. That transmission between hosts is the defining feature here, which is why this term fits best. Cancer is about uncontrolled cell growth inside one person, not a pathogen spreading between individuals. The immune response is the body's defense against such threats, not a disease itself. An antibiotic is a treatment for bacterial infections, not a disease.

Infectious disease describes illnesses caused by pathogens—bacteria, viruses, fungi, or parasites—that can be passed from one living thing to another. That transmission between hosts is the defining feature here, which is why this term fits best. Cancer is about uncontrolled cell growth inside one person, not a pathogen spreading between individuals. The immune response is the body's defense against such threats, not a disease itself. An antibiotic is a treatment for bacterial infections, not a disease.