LIVER-
Most useful organ for excretion because it is used in multiple functions.
Liver helps in removal of toxins and poisonous substances and removes toxins from blood also.
Liver helps in removing bilirubin which forms after breakdown of hemoglobin.
Also used in removal of ammonia because it converts ammonia into urea by Nitrogen cycle.
LUNGS-
Lungs are respiratory organs of the body which help in removing carbon dioxide from the body.
SKIN-
Skin is also most important in removal of excretion, it helps in formation of sweat by sweat glands.
Sweat helps in removing impurities and dust from skin, excess of salt and very small amounts of urea.
Final Answer:
LIVER-
Most useful organ for excretion because it is used in multiple functions.
Liver helps in removal of toxins and poisonous substances and removes toxins from blood also.
Liver helps in removing bilirubin which forms after breakdown of hemoglobin.
Also used in removal of ammonia because it converts ammonia into urea by Nitrogen cycle.
LUNGS-
Lungs are respiratory organs of the body which help in removing carbon dioxide from the body.
SKIN-
Skin is also most important in removal of excretion, it helps in formation of sweat by sweat glands.
Sweat helps in removing impurities and dust from skin, excess of salt and very small amounts of urea.