Question

Kidney of frog is
A. Pronephros
B. Mesonephros
C. Opisthonephron
D. Metanephros

Answer 1

Hint: The most common species of frog found is Rana tigrina. They belong to class amphibians which means they can live on both land and fresh water. They are uricotelic which means they excrete urea.

Complete answer:
A frog tailless amphibian belongs to the order Anura. Some frog species are known as toads but they are not distinguishable from each other not from taxonomy or evolutionary history.

The excretory system of frog consists of
- Pair of kidneys
- Ureters
- Cloaca
- Urinary bladder

Kidneys are dark red bean shaped structures situated posteriorly in the body cavity on both sides of the vertebral column. Each kidney is composed of uriniferous tubules or nephrons which are structural and functional units of the kidney.

In male frog, two ureters emerge from the kidney. The ureter behaves as a urinogenital duct which further opens into the cloaca. The urinary bladder is present ventral to the rectum which also opens in the cloaca. The frog excretes urea from the body that’s why they are known as uricotelic animals. Blood carries the excretory waste to the kidney where it is separated and excreted.

- Opisthonephros is a type of kidney-formed from the expanded mesonephros. It is also known as adult kidney in most fishes and amphibians.
- Pronephros is one of the excretory organs that develop in vertebrates and which further correspond to the first stage of kidney development.
- The mesonephros is also one of three excretory organs that develop in vertebrates. It acts as the main excretory organ of aquatic vertebrates.
- Metanephros is the permanent and functional kidney present in higher vertebrates.

Hence, the correct answer is option (C).

Note: Frogs are cold blooded animals or poikilotherms because they do not have constant body temperature which means their temperature varies with the temperature of the environment. Frogs have an ability to change their colour to hide them from their enemies. This protective coloration is known as mimicry.