Question

Some protists (like some bacteria) are parasitic. That is they are parasites! What does that mean? What kind of relationship does a parasite have with their host (start using plus (+) to designate a beneficial association and minus (-) to designate harmful association)? Are both benefiting?

Answer 1

Parasitism describes a symbiotic relationship where the parasite benefits at the host's expense. Parasites live in or on their hosts and take nutrients without typically killing them quickly to ensure the continuation of their reproductive cycle.

Step-by-step explanation:

A parasite is an organism that lives in or on another living organism (called the host) and derives nutrients from it. In this symbiotic relationship, which is known as parasitism, the parasite benefits (+), while the host is harmed (-). The host, in this parasitic interaction, usually becomes weakened because the parasite siphons resources that the host would typically use to maintain itself. However, a parasite rarely kills the host quickly since it relies on the host's survival for its reproductive cycle. In contrast to parasites, pathogens also harm the host by causing disease, damaging host tissues, or physiology.

Parasitic protists, like some bacteria, can either be internal, living inside the host's body, or external, living on the host's surface. Despite the harm they can cause, parasites are very common in nature, and almost every multicellular animal or plant typically harbors some form of parasite. Parasites must often become resistant to the host's natural defense mechanisms to survive and thrive within or upon their hosts.