parazity
Parazity, or parasites, are organisms that depend on another living organism—the host—for nutrients and survival, typically harming the host. They can live inside the host (endoparasites) or on its surface (ectoparasites). They may complete their life cycles with a single host or require one or more intermediate hosts or vectors (indirect life cycles). Major groups include protozoa (single-celled parasites), helminths (multicellular worms such as nematodes, cestodes, and trematodes), and arthropods that feed on host tissues or blood (fleas, lice, ticks, mites). Transmission methods vary: ingestion of contaminated food or water, skin penetration, or transfer by vectors such as mosquitoes, ticks, or snails.
Life cycles often involve adaptations to evade host defenses, reproduce efficiently, and spread to new hosts.
Prevention and control rely on sanitation, clean water, vector management, safe food handling, and antiparasitic medications;