excretion

Question 1

what is excretion?

Answer 1

excretion is the removal of toxic materials/metabolic waste products from the body via either the lungs or the kidneys

Question 2

how are metabolic waste products formed and why are they harmful?

Answer 2

metabolic waste products are products formed from chemical reactions occuring within cells, eg, urea is formed from the deamination of excess amino acids in the liver. when allowed to accummulate, these metabolic waste products become toxic

Question 3

how do the kidneys carry out excretion?

Answer 3

they remove urea from the circulating blood. they also regulate the water levels and ph of the blood. it excretes excess water in the form of urine

Question 4

how do the lungs carry out excretion

Answer 4

the lungs carry out excretion by excreting carbon dioxide and water vapour, which are excreted via the lungs