paraziter

Paraziter is a biological term for an organism that lives in or on another organism (the host) and derives resources at the host's expense. Parasites range from microscopic protozoa to macroscopic worms and arthropods. They include Plasmodium, nematodes, cestodes, ticks, and lice. Parasites can infect plants, animals, and humans, and many have complex life cycles involving one or more hosts or vectors.

Parasites are typically categorized as endoparasites (inside the host) or ectoparasites (on the host surface). They can be obligate, requiring a host to complete their life cycle, or facultative, able to live free-living or parasitic stages. Host range varies from highly specific to broad, with some parasites infecting multiple species.

Interactions with hosts often include attachment, feeding on nutrients, and evading immune defenses. Parasites may cause disease or weaken health, and some use specialized adaptations such as tissue migration, antigenic variation, or sheltered niches to persist. Transmission routes include direct contact, ingestion of contaminated material, or vectors like mosquitoes and ticks.

Impact and management: Parasites contribute to human and animal disease burdens and economic losses in agriculture. Control approaches emphasize sanitation, vector control, anthelmintic drugs, and, in some cases, vaccines and surveillance. Ecologically, parasites influence population dynamics and food webs and may play roles in biodiversity and host–parasite coevolution.