Question

Malpighian tubules are
(a)Excretory organs of insects.
(b)Excretory organs of frogs.
(c)Respiratory organs of insects.
(d)Endocrine glands of insects.

Answer 1

Hint: 2/3rd population of the animal kingdom is of these animals. They have specialised organs for their removal of wastes and this system is unique to these organisms.

Complete answer:
Malpighian tubules help to remove the wastes from their body by making urine and solid nitrogenous waste, which are then excreted from the body. It is a tubule that extends from the alimentary canal to the exterior of the organism, excreting water and wastes in the form of solid nitrogenous compounds.
Example: Cockroach, Grasshoppers and other insects etc.

Additional Information:
Structure: Malpighian tubules are slender tubes normally found in the posterior regions of arthropod alimentary canals. Each tubule consists of one layer of cells that is closed off at the distal end with the proximal end joining the alimentary canal at the junction between the midgut and hindgut. Most tubules are normally highly convoluted. the amount of tubules varies between species although most occur in multiples of two.
Mode of action:
Pre-urine is made within the tubules when nitrogenous waste and electrolytes are transported through the tubule walls. Wastes like urea and amino acids are thought to diffuse through the walls, while ions like sodium and potassium are transported by active pump mechanisms. Water follows thereafter. The pre-urine, alongside digested food, merge within the hindgut. At this point, the uric acid precipitates out, and sodium and potassium ions are actively absorbed by the rectum, alongside water by the process of osmosis. Uric acid is left to combine with faeces, which are then excreted.

So, the correct answer is,” Excretory system of insects.”

Note: The main function of the Malpighian tubules of insects is the excretion of the nitrogenous products and other remains of metabolites. Different organisms have different types of excretory systems where all perform a common function called the removal of wastes or unwanted substances from the bodies.