Question: 153: Nitrogenous waste is excreted in the form of pellet or paste by :
(1) Hippocampus
(2) Pavo
(3) Ornithorhynchus
(4) Salamandra
Answer: Option (2)
Explanation:
Animals excrete nitrogenous wastes in different chemical forms based on their habitat and water availability.
Pavo is a bird, and birds are uricotelic organisms.
Uricotelic animals excrete nitrogenous waste mainly in the form of uric acid.
Uric acid is semi-solid and is excreted as pellets or paste, which helps in conserving water.
Hippocampus is a fish and excretes ammonia.
Ornithorhynchus is a mammal and mainly excretes urea.
Salamandra is an amphibian and is also ureotelic.
Therefore, nitrogenous waste is excreted in the form of pellet or paste by Pavo.