Final answer:
Zoomastigina that are parasites get nourishment from a host organism, benefiting from the nutrients they siphon while typically harming the host by weakening it.
Step-by-step explanation:
Zoomastigina that are parasites get nourishment from a host organism. These parasitic organisms live in or on the host and derive nutrients essential for their survival. In this parasitic relationship, the parasite benefits by obtaining resources such as food or shelter, while the host is typically harmed, as it loses nutrients and energy to the parasite.
Examples of parasitic relationships include the tapeworm Taenia, a helminth that feeds from its host's gut, and may grow exceedingly long. Another example is the Nematodes like Dracunculus medinensis and Ancylostomiasis, which infect humans and other animals. There are also protozoan parasites like Plasmodium falciparum, the cause of malaria, which spreads through mosquito vectors.
While these parasites can have a negative impact on the host by weakening it and potentially causing disease, they generally do not kill the host quickly, as a fast death would not allow them to complete their reproductive cycle and spread to new hosts.