Question

Match the excretory organs with the animals given. Choose the answer which gives the correct combination of alphabets of the two columns.

List 1	List 2
A)Nephridia	1.Octopus
B)Malpighian tubules	2.Cockroach
C)Protonephridia	3.Shark
D)Kidneys	4.Tapeworm

A)A=2,B=4,C=3,D=1
B)A=1,B=2,C=4,D=3
C)A=4,B=2,C=1,D=5
D)A=2,B=5,C=4,D=3

Answer 1

Hint: The excretory system is an important biological system responsible for removing the unwanted materials from the body fluids and helps in maintaining internal chemical homeostasis therefore preventing damage to the body.

Complete answer:
In case of most invertebrates, the excretory structures have simple tubular shapes, but in vertebrates they have a complex tubular organ called as kidneys. Shark is a vertebrate that has kidneys as an excretory structure.
Protonephridia, also called as flame cells are found as excretory structures in Platyhelminthes (Flatworms, e.g., Planaria), rotifers and the cephalochordate Amphioxus. Protonephridia is mainly concerned with the control of ionic and fluid volume, i.e. osmoregulation.
Nephridia is a tubular excretory structure of earthworms and other annelids such as Leech. Nephridia helps to eliminate nitrogenous waste and maintain a fluid and ion balance.
Malpighian tubules are the excretory structures of most insects, including cockroaches. Malpighian tubules aid in the removal of nitrogen waste and osmoregulation.

Hence, the correct answer is option (B)

Note: Metabolic wastes or excrements are products left over from metabolic processes such as cell respiration, which cannot be utilized by the organism (they are surplus or toxic) and must thus be excreted. They contain nitrogen compounds, water, $CO_2$, phosphates, sulphates, etc. Animals regard these substances as excreta. Plants have chemical machines that transform some of them (primarily nitrogen compounds) into useful substances.