The correct answer is (d), Birds and Lizards both.
Uric acid is a nitrogenous waste product that is produced when the body breaks down proteins. It is a white, crystalline solid that is soluble in water. Uric acid is excreted in the urine.
Humans, birds, and lizards are all ureotelic animals, which means that they excrete uric acid as their primary nitrogenous waste product. Uric acid is a relatively insoluble substance, so it is less toxic than other nitrogenous waste products, such as ammonia. This is an advantage for animals that live in dry environments, where water is scarce.
In humans, uric acid is produced in the liver and then excreted in the urine. The kidneys play a role in regulating the levels of uric acid in the blood. If the levels of uric acid in the blood become too high, it can lead to the formation of kidney stones.
In birds, uric acid is produced in the kidneys and then excreted in the form of a white paste. The birds’ kidneys are very efficient at excreting uric acid, which is why birds do not need to drink as much water as other animals.
In lizards, uric acid is produced in the liver and then excreted in the form of a white paste. The lizards’ kidneys are also very efficient at excreting uric acid, which is why lizards do not need to drink as much water as other animals.