Human Health and Disease — BIOLOGY STD 12 Science — Question

3. Man

Explanation:

A parasite that lives on the surface of a host organism. Some are host specific like louse is the ectoparasite for humans. It sucks the blood from the humans.

They usually spend their whole life on a single host, cementing their eggs, which are known as nits, to hairs or feathers. The eggs hatch into nymphs, which moult three times before becoming fully grown, a process that takes about four weeks.