Question

In the life cycle of Wuchereria bancrofti causes infection in humans
A) Microfilaria
B) 1st stage larva
C) 2nd stage larva
D) 3rd stage larva

Answer 1

Hint: Wuchereria bancrofti is a filarial nematode that causes lymphatic filariasis. It is one of three parasitic worms that infect the lymphatic system to induce lymphatic filariasis, together with Brugia malayi and B. timori.

Complete answer:
Life Cycle of Wuchereria bancrofti
When male and female nematodes mate, the female viviparously releases microfilariae (first stage larvae or L1), which pass through the circulatory system and accumulate in lung arterioles throughout the day before emerging at night (if nocturnally periodic) when night biting mosquitoes are most involved.
Once the microfilariae have reached a suitable mosquito host via a blood meal, they penetrate the insect's gut wall and pass to the thoracic muscles, where they develop (via two life stages) into third-stage infective larvae.
Following third stage larvae infection, there is normally a phase of robust immune response to the invading larvae.
If the larvae are not removed from the body during this period, the pathologies associated with filarial infection may develop. The majority of these disorders do not seem to be caused by the nematodes themselves, but rather by immune responses to their presence.
The most visible of these is damage to lymphatic vessels caused by the immune system's reaction to adult worms living in them. These immune responses (Lymphangitis) are distinguished by inflammation of the infected region (usually the extremities) and fever.

Thus, 3rd stage larva In the life cycle of Wuchereria bancrofti causes infection in humans.

Note:
The parasite Wuchereria bancrofti is responsible for the majority of filariasis cases. Mosquitoes such as Culex, Aedes, and Anopheles serve as vectors for W. bancrofti in the transmission of the disease.