- These genes are essentially immune system genes and defend the host organism from parasites.
- After all, more than half the species on Earth are parasites, and most organisms are host to a number of them.
- Some water molds are parasites on other organisms; they may grow on the scales or eggs of fish, or on amphibians.
- MPs, councillors and all their cronies are nothing more than scroungers, spongers, parasites.
- They are literary parasites, the enemies of creativity and imagination.
- They are all a pack of bludgers and parasites who pay no taxes but spend ours.
Parasites exist in huge variety, including animals, plants, and microorganisms. They may live as ectoparasites on the surface of the host (e.g., arthropods such as ticks, mites, lice, fleas, and many insects infesting plants) or as endoparasites in the gut or tissues (e.g., many kinds of worm), and cause varying degrees of damage or disease to the host