NEET Class neet Answered

(i) A characteristic feature of lymphatic filariasis in most endemic areas is the nocturnal periodicity of microfilaremia whereby peak levels of parasites appear in peripheral blood at night when the mosquito vectors are seeking a blood meal. Wuchereria bancrofti is a human parasitic worm (filarial worm) that is the major cause of lymphatic filariasis. Hence, Wuchereria bancrofti  microfilaria show nocturnal periodicity.

(ii) Spirochaetes are flexible spirally twisted bacteria, especially the ones which cause syphilis.