5.1.2 (a) Excretion

Question 1

what is excretion?

Answer 1

the removal of waste products of metabolism from the body

Question 2

what are the main metabolic waste products in mammals?

Answer 2

carbon dioxide
bile pigments
nitrogenous waste

Question 3

how is carbon dioxide produced as a waste product?

Answer 3

it is a waste product of cellular respiration which is excreted from the lungs

Question 4

how are bile pigments a waste product?

Answer 4

formed from the breakdown of haemoglobin in old red blood cells in the liver

Question 5

how is nitrogenous waste a waste product?

Answer 5

formed during the breakdown of amino acids in the liver

Question 6

what do mammals produce as nitrogenous waste?

Answer 6

urea

Question 7

what do fish produce as nitrogenous waste?

Answer 7

ammonia

Question 8

what do birds and insects produce as nitrogenous waste?

Answer 8

uric acid

Question 9

why is excretion important?

Answer 9

to stop the buildup of toxic waste products in the body

Question 10

why is the excretion of carbon dioxide important?

Answer 10

too much CO2 in the blood is toxic so it needs to be removed

Question 11

how is excretion involved in homeostasis?

Answer 11

by excreting waste products the body is able to maintain homeostasis by keeping levels of certain substances in the blood constant

Question 12

what is metabolism?

Answer 12

all the chemical reactions which happen in cells