Question

Nocturnal periodicity is exhibited by
A. Wuchereria
B. Ascaris
C. Rhabditiform
D. Microfilaria

Answer 1

Hint: The larva which causes lymphatic filariasis circulates in the blood at night. It is most abundant in the circulation at night. These are absent in the blood during daytime.

Complete answer:
Animals that are diurnal are usually awake and active during the day. Nocturnal means which are active during night time. Some animals can be both. Some animals are neither diurnal or nocturnal. A circadian rhythm with the periodicity expressed during night time and they are less active during day time. Nocturnal periodicity is exhibited by microfilarial larva of human filaria wuchereria bancrofti into the peripheral blood. Microfilariae were found to have great difficulty in passing through the peripheral capillaries. The microfilariae is an early life stage in the life cycle of certain parasitic nematodes in the family Onchocercidae. In these species the adults live in a tissue or the circulatory system of vertebrates or hosts. Microfilariae are less active in day blood than in night blood. As they are not able to work their way through the capillaries in the daytime, hence the mechanism of nocturnal periodicity. Microfilariae can live in the host up to 12 months and adult worms take 6-12 months to develop from the larval stage and can live between 4-6 years.

So, the correct answer is option D.

Note: This type of periodicity is found in religions where the vector mosquito is a night biting species. These are widely found in tropical and subtropical zones in Africa, Asia, and latin America in which microfilarial densities peak close to midnight.