What is a primary characteristic of a parasite?

A primary characteristic of a parasite is that it requires a host for survival. Parasites are organisms that live on or within a host organism, obtaining nutrients at the host’s expense. This dependency on a host for resources is crucial for the parasite's growth, reproduction, and overall existence.

In contrast to the other options, a parasite does not live independently; instead, its life cycle and development are intricately linked to its host. Parasites typically do not provide more energy to their host, as their primary function is to extract nutrients, often causing harm. Additionally, unlike plants or certain microorganisms, parasites do not produce their own food through photosynthesis; they rely entirely on the host's biological systems for sustenance. Thus, the defining trait of a parasite is its obligate relationship with a host for survival and nutrition.