What term describes an organism that depends on another organism for survival?

The term that accurately describes an organism that depends on another organism for survival is "parasite." Parasites rely on a host organism to fulfill their nutritional and reproductive needs. They often live on or inside the host, benefiting at the host's expense, which can lead to detrimental effects on the host's health.

In contrast, a symbiont refers to organisms that live together in a close relationship, which can be mutualistic, commensal, or parasitic. In mutualism, both organisms benefit, while in commensalism, one benefits without harming the other. Pathogens are a specific type of parasite that causes disease but may not necessarily fit the broad definition of dependency for survival. A host refers to the organism that supports the parasite, meaning it does not describe the parasite itself but rather the organism being exploited.