Question

Antennary gland is the excretory organ of
(A)Mosquito
(B)Cockroach
(C)Palaemon
(D)All of the above

Answer 1

Hint: Excretory system is one of the important organ systems that play a role in the excretion of body waste or unnecessary body fluids material. The excretory system helps in maintaining internal chemical hemostasis means equilibrium between various chemicals and also prevents any damage to the body.

Complete answer:The excretory system regulates water balance among the various body fluids. Different organisms have evolved different excretory glands for excretion. Lower animals remove their waste products from their body surface.

Antennary glands are opaque-white, pea-sized structures present in the coxa of each second antenna.they are also called ‘Green glands’. These are osmoregulatory organs of Crustaceans like Prawn, Crayfish, Palaemon and many more. The labyrinth of antennal gland also causes reabsorption of glucose, amino acids and divalent ions from tubular fluids.

The most advanced mechanism to excrete waste is present in Humans which include a pair of kidney, ureter and urinary bladder. They purify the blood and help in excretion of blood waste such as ammonia, urea, uric acid through urine. A nephron is the excretory unit which is responsible for reabsorption of main electrolytes such as sodium, potassium, bicarbonate ions.

Mosquito and Cockroach remove their waste products through an organ called Malpighian tubules.
An earthworm has Nephridia as its excretory organ.

So, the correct answer is Option (C) Palaemon.

Note: Excretion is different from Defecation. Removal of solid waste products through faeces is termed as Defecation. Defecation involves the digestive system and the waste is stored in the rectum and the faeces is passed through the anus. Faeces contain solid metabolic waste. The food we eat gets digested, absorbed and the waste product is removed in the form of faeces.