Write notes on uricotelism.
Answers
Answered by
5
Elimination of uric acid as the main nitrogenous waste material is called uricotelism. Animals showing uricotelism are called uricotelic animals.
It is a common method seen in birds, land reptiles, insects, land snails and some land crustaceans.
Uric acid is formed from ammonia mostly in the liver and to some extent in the kidneys. The process is highly energy dependant, but is much less toxic than both ammonia and urea and it is almost insoluble in water and can be eliminated from the body in nearly a solid state, saving a lot of water. Since kidneys can handle the nitrogenous wastes only in solution, reptiles and birds pass a dilute solution of uric acid into the cloaca, where water is absorbed and solid uric acid is eliminated along with faeces. The faecal matter of certain birds like cormorants, pelicans and gannets called guano has been used for the commercial extraction of uric acid. Islands off the coast of South America are covered with guano.
Man also excretes a small amount of uric acid in his urine formed by the catabolism of nucleic acids.
Other Nitrogenous wastes - Allantosm, creatine, creatinine and hippouric acid are some other nitrogenous waste products excreted by mammals.
The excretory systems also show the process of evolution from simple to complex. For example flatworms like planaria have the simplest tubular excretory system called the protonephridia. Rotifers and cephalochordates also possess protonephridia. The protonephridium is a network of closed tubules some of which terminate into flame cells. These flame cells help to collect the fluids and send them out through nephridiopores which are numerous openings or pores connected to the body surface
It is a common method seen in birds, land reptiles, insects, land snails and some land crustaceans.
Uric acid is formed from ammonia mostly in the liver and to some extent in the kidneys. The process is highly energy dependant, but is much less toxic than both ammonia and urea and it is almost insoluble in water and can be eliminated from the body in nearly a solid state, saving a lot of water. Since kidneys can handle the nitrogenous wastes only in solution, reptiles and birds pass a dilute solution of uric acid into the cloaca, where water is absorbed and solid uric acid is eliminated along with faeces. The faecal matter of certain birds like cormorants, pelicans and gannets called guano has been used for the commercial extraction of uric acid. Islands off the coast of South America are covered with guano.
Man also excretes a small amount of uric acid in his urine formed by the catabolism of nucleic acids.
Other Nitrogenous wastes - Allantosm, creatine, creatinine and hippouric acid are some other nitrogenous waste products excreted by mammals.
The excretory systems also show the process of evolution from simple to complex. For example flatworms like planaria have the simplest tubular excretory system called the protonephridia. Rotifers and cephalochordates also possess protonephridia. The protonephridium is a network of closed tubules some of which terminate into flame cells. These flame cells help to collect the fluids and send them out through nephridiopores which are numerous openings or pores connected to the body surface
Answered by
4
URICOTELISM
It is the process of excretion of nitrogenous wastes in the form of uric acid and its salts ‘urates’. Some of the uricotelic animals are insects, birds and reptiles like snakes and desert animals.
Due to its low solubility in water, it is excreted as a pasty white substance in very small quantities.
Its less toxicity makes the body more tolerant even in high concentrations.
This is an important adaptation in animals in water-deficient areas like deserts.
There are two other means by which the other forms of nitrogenous wastes are excreted in other living beings.
Ammonotelism - Ammonia is excreted (protozoans, crustaceans, freshwater fish, etc.)
Ureotelism - Urea is eliminated (man, higher animals, marine fish, etc.)
Similar questions