What is the primary nitrogenous waste excreted by frogs?

The correct answer is Option (2) - Urea

Frogs are ureotelic animals, meaning they excrete urea as the main nitrogenous waste. Urea is a less toxic compound compared to ammonia and allows for efficient elimination of nitrogenous waste in a terrestrial environment. Urea is produced in the liver, transported through the bloodstream, and excreted by the kidneys. This process helps frogs conserve water and adapt to life on land.

Two ureters emerge from the kidneys in the male frogs. The ureters act as urinogenital duct which opens into the cloaca. In females the ureters and oviduct open seperately in the cloaca. The thin-walled urinary bladder is present ventral to the rectum which also opens in the cloaca. The frog excretes urea and thus is a ureotelic animal. Excretory wastes are carried by blood into the kidney where it is separated and excreted.