Question

Archinephros occurs in
A. Adult hagfish
B. Larva of hagfish
C. Molluscs
D. Anamniotes

Answer 1

Hint: Archinephros are the ancestral vertebrate kidneys that are retained by some caecilians. This occurs in the embryos of the higher animals. Here we are going to see about the occurrence of the archinephros and find them from the options given. Through some of the information, it could be found and analyzed.

Complete answer: Archinephros is the primitive kidney that is occurring in the larvae of the hagfish. This majorly occurs in the embryos of the higher animals as the excretory organ in the simplest kind. This is non-functional in humans as well as in other mammals. There are about three types that come under this category. Hagfish here belongs to the class myxine. These may extend from the anterior to the posterior of the body. These are segmentally arranged in both of the glomeruli as well as the nephrostomes. Glomeruli receive the blood from the dorsal aorta and are filtered nitrogenous wastes that are collected from the nephrostomes and these are transported outside through the collecting ducts as well as archinephric ducts. They also imply the kidney of the ancestral vertebrate. Hence, the archinephros occurs in the adult hagfish.
So, the correct answer is “Option A”.

Note:
Archinephros includes the pair of kidneys that runs through the entire length of the coelom. These have the tubules which are arranged segmentally and one set of pairs per the body segment. These may carry urine from the primitive kidneys to the primitive bladder. These are the importance of the archinephros.