Excretion and Homeostasis questions and answers

 

Q:      What is excretion. Name the important waste products.?

 

Ans:-  EXCRETION

Excretion may be defined as the removal of waste materials or any other substances which are not needed in the cell activities .

 

The important excretory or waste products are the nitrogenous materials and carbon dioxide. Oftenly water is also produced in excess. The predominant nitrogenous excretory materials are ammonia, urea or uric acid. Therefore, they must be removed from the body.

 

 

     Q:  What general relationships exist between the environment in which an organism lives and its method of excreting nitrogenous wates?

 

Ans:-  RELATIONSHIP BETWEEN ENVIRONMENT AND NITROGENOUS WASTES

 

Theare exist a general relationship between the environment of the organism and the kind of the nitrogenous waste and its methods of removal.

AMMONIA

              

             Ammonia is the waste product of those animals that live in water. Ammonia is an immediate nitrogenous product of protein and amino acid metabolism. It is very toxic and removed by simple diffusion into the surrounding water without fear of self-intoxication.

UREA

          

           Urea is formed from ammonia. It is also harmful to cells but less than ammonia. Urea can easily be excreted by animals that have adequate water supply for this purpose, or special body mechanisms that save water , man use at least a litre of water each day to carry away the urea our cells produce.

URIC ACID

          

               Uric acid is the waste product of those animals which have little supply of water, insects, many birds etc. It is insoluble and comparatively harmless. It also needs very little water for its removal.