What is a facultative parasite?

A facultative parasite is best described as a pathogen that primarily obtains nutrients from dead organic material but has the capability to exploit living organisms when the opportunity arises. This adaptability allows facultative parasites to thrive in various environments. They can switch between saprophytic (feeding on dead matter) and parasitic lifestyles, depending on the availability of resources in their surroundings.

This definition is crucial, as it signifies a level of versatility that can impact plant health. By utilizing living hosts when accessible, these pathogens can exhibit opportunistic behavior, potentially leading to disease in otherwise healthy plants. Understanding this characteristic is essential for effective management and control of such pathogens in agricultural and horticultural practices.

The other options do not accurately reflect the nature of a facultative parasite: the first option implies strict dependency on living hosts, the third describes benefit rather than parasitism, and the fourth indicates a non-pathogenic cause of disease.