Question

Which type of kidney is found in amphibians?
A. Holonephric
B. Mesonephric
C. Pronephric
D. Metanephric

Answer 1

Hint: Amphibians are small vertebrates that need water or a humid environment to survive. The species in this group include frogs, toads, salamanders, newts, etc. These organisms have a specialized type of kidneys that have tubular nephrons.

Complete answer: The kidneys are made up of about a million filter units called nephrons. Each nephron contains filters called glomerulus and tubules. The nephron works in two steps: the glomerulus filters the blood, and the tubules return necessary substances to your blood, removing wastes. The kidneys that are found in amphibians are mesonephric. It develops from the middle part (mesonephros) of the nephrostome plate and the remaining part of the nephrostome is destroyed. Only Bowman's capsule is found in nephrons while the remaining part is a simple tubular. Most of the Amphibians and fishes have this type of kidneys.
1. Pronephric kidney: It develops from the front (pronephros) of the nephrostome plate. The nephron is only tubular. For example, the Cyclostome and the frog spoon.
2. Metanephric Kidney: It develops from the back (metanephros) of the nephrostome while the rest is destroyed. Nephrons are well differentiated in the Bowman's capsules, PCT, DCT and Henle’s capsule chains. Examples; reptiles, aves and mammals.
Thus, the option (B) is correct.

Note: The holonephric kidneys produce tubules in the anterior to posterior sequence during development. From each segment, two nephrotomes emerge, each with a glomerulus, nephrocoel, and nephric tubule, all of which are connected to form an archinephric canal.