Question

Fill up the blank spaces in the table below by selecting the correct option.

Phylum/Class	Excretory organ	Circulatory organ	Respiratory organ
Arthropoda	A	B	Lungs/Gills/Tracheal system
C	Nephridia	Closed	Skin
D	Metanephridia	Open	E

(A) A-Green gland, B-Closed, C-Mollusca, D-Annelida, E-Tracheal system.
(B) A-Malpighian tubule, B-Open, C-Annelida, D-Mollusca, E-Feather like-gills.
(C) A-Antennary gland, B-Open, C-Porifera, D-Amphibia, E-Lungs.
(D) A-Nephridia, B-Closed, C-Mollusca, D-Annelida, E-Lungs.

Answer 1

Hint: The above mentioned are related to the phylum of Animal Kingdom and are inter-connected to each other in some sorts. So we have to fill up the column i.e. which organisms have which type of organs i.e. excretory, respiratory as well as circulatory organ respectively in a correct manner.

Complete answer:
Arthropoda is believed to be an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages. From this phylum, Arthropods are formed up which consists of insects, arachnids, myriapods and crustaceans. They have Malpighian tubules present as their excretory system. These are slender tubes normally found in the posterior regions of arthropod alimentary canals. Each tubule contains a single layer of cells that is closed off at the distal end with the proximal end connecting the alimentary canal at the junction between the midgut and hindgut. Arthropods have an open circulatory system where the blood is pumped out into a cavity called a hemocoel where it surrounds the organs and then returns to the heart via Ostia which is the opening. The blood found in arthropods, a mixture of blood and interstitial fluid is called 'hemolymph'.
Annelidan have nephridia present as their excretory organ. It is a tubule which is open to the exterior which acts as an organ of excretion or osmoregulation. It typically has ciliated or flagellated cells and absorptive walls.
Metanephridia are the excretory organs of Phylum-Mollusca. They are known to be the excretory gland found in many types of invertebrates such as Annelida, Mollusca, Arthropods, etc.
At last but not the least, molluscs have the feather-like gills as their respiratory organ.

Hence, the correct answer is an option (B). A-Malpighian tubules, B-Open, C-Annelida, D-Mollusca, E-Feather like-gills.

Note:
In molluscs, the space available between the mantle and the hump is known to be as the mantle cavity in which the feather-like gills are present. They act as both respiratory and excretory functions.