Q.Which of the following is an ectoparasite commonly found on humans?
(A) Ascaris (roundworm)
(B) Tapeworm
(C) Head louse (Pediculus)
(D) Plasmodium

An ectoparasite lives on the OUTER surface of its host's body. The head louse (Pediculus) attaches to human hair and the scalp and feeds on blood from the surface, making it a clear example of an ectoparasite. Ascaris (option A), a roundworm, lives inside the human intestine, making it an endoparasite, not an ectoparasite. Tapeworm (option B) also lives inside the human intestine, absorbing nutrients directly from the host's gut — another endoparasite. Plasmodium (option D), the malarial parasite, lives i …

Sort each option by where it lives — Ascaris, tapeworm, and Plasmodium are all INSIDE the body (endoparasites); only the head louse is on the OUTER surface (ect …

Do not pick any of Ascaris, tapeworm, or Plasmodium — all three are well-known ENDOparasites (living inside the host), whic …