Question

In prawn, excretion is carried out by
(a)Nephron
(b) Malpighian tubes
(c)Flame cells
(d)Green glands

Answer 1

Hint: Crustaceans and arachnids possess paired excretory organs (maxillary, antennal, or coxal glands) that open at the bases of certain appendages. The excretory organs of a prawn consist of a pair of cream-colored antennary glands with their ducts, a median renal sac, and a transverse communicating duct. It also performs the function of osmoregulation.

Complete answer:
Excretion, the process by which animals rid themselves of waste products and the nitrogenous by-products of metabolism. Through the excretion process, the organisms control osmotic pressure—the balance between inorganic ions and water—and maintain acid-base balance.
Prawns are arthropods. In Prawn, excretion is carried out by green glands. They have one pair of green glands. It filters the nitrogenous waste from the body. It opens at the base of each antenna. They perform excretion as well as osmoregulation. The excretion by the green glands is supplied with blood by the antennary arteries. Water and dissolved substances pass into the end-sacs by ultrafiltration. The filtrate passes into the labyrinth. By selective reabsorption, the useful products are returned to the blood in the labyrinth. It flows into the bladders after then the urine is collected and also the excretory fluid comes here from the renal sac. The urine is passed out through the ureters and renal apertures. And in the process of osmoregulation, water enters into the body regularly by osmosis. The water is collected and sent out by green glands. Prawn passes out a huge quantity of water with urine to maintain osmoregulation.

Additional Information: 1)Palaemon excretory system also contains a median sac called renal sac which is a large median sac present beneath the dorsal shield. It covers the entire cardiac stomach. It is connected with the bladder of each antennary gland anteriorly by a lateral duct.
2)The antennary glands show three parts: the end – sac, labyrinth, and bladder.
3)The end-sac is the central part of the antennary gland. It has epithelium and outer connective tissue. The end-sac contains a large lacuna in its cavity. It opens into the labyrinth by a pore.
4)Labyrinth is a mass of branched excretory tubules held together by connective tissue. The wall of each excretory tubule is formed by excretory epithelium.
5)Bladder is placed on the inner side of the end-sac. It opens into the renal sac by the lateral duct. It gives an excretory duct or ureter, from its inner side. It opens out by the excretory or renal aperture on the inner side of the coxa of the respective antenna.
6) With the molting of the chitinous integument, the nitrogenous products deposited in the integument also get rid of. Thus integument is believed to be an important excretory organ of prawn.
So, the correct answer is ’green glands’.

Note: The waste products and excess fluids are filtered out by kidneys and excrete them as urine, via the bladder. After that, the clean blood flows back to the other parts of the body. It will cause damage to our body if our kidneys did not remove this waste.