Question

Write short notes on the following: (i) Filariasis (ii) Polyembryony

Hint:

Filariasis = mosquito-borne disease caused by filarial worms. Polyembryony = more than one embryo from a single fertilized egg.

Answer 1

(i) Filariasis: \[\begin{array}{rl} \bullet & \text{Filariasis, also called elephantiasis, is a disease caused by filarial worms such as Wuchereria bancrofti and Wuchereria malayi.} \\ \bullet & \text{It is transmitted by the bite of female Culex mosquitoes.} \\ \bullet & \text{The adult worms live in the lymphatic vessels of the human body, blocking lymph flow.} \\ \bullet & \text{Symptoms: Swelling of legs, scrotum, and breasts (elephant-like appearance), fever, and repeated inflammation of lymph nodes.} \\ \bullet & \text{Control: Use of mosquito nets, anti-filarial drugs like DEC (diethylcarbamazine), and eradication of mosquito breeding sites.} \\ \end{array}\] (ii) Polyembryony: \[\begin{array}{rl} \bullet & \text{Polyembryony is the phenomenon of formation of more than one embryo from a single fertilized egg (zygote).} \\ \bullet & \text{It was first discovered by Leeuwenhoek in orange seeds.} \\ \bullet & \text{It may be of two types:} \\ \bullet & \text{True polyembryony: More than one embryo arises from the same zygote due to cleavage (e.g., identical twins in humans).} \\ \bullet & \text{False polyembryony: Additional embryos arise from accessory embryos or other cells of the ovule.} \\ \bullet & \text{Examples: Occurs naturally in plants like citrus, onion, and in animals like armadillos.} \\ \end{array}\]