Chapter 13: Excretion

Question 1

How is carbon dioxide excreted?

Answer 1

excreted through the lungs

Question 2

What does the kidney excrete?

Answer 2

urea and excess water and ions

Question 3

Structure of kidney

Answer 3

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Medulla inside
Cortex outside

Question 4

Function of nephrons

Answer 4

(a) the role of the glomerulus in the filtration from the blood of water, glucose, urea and ions
(b) the role of the nephron in the reabsorption of all of the glucose, some of the ions and most of the water back into the blood
(c) the formation of urine containing urea, excess water and excess ions

Question 5

Describe the role of the liver

Answer 5

the assimilation of amino acids by converting them to proteins

Question 6

Where is urea formed

Answer 6

It is formed in the liver from excess amino acids

Question 7

Describe deamination

Answer 7

the removal of the nitrogen-containing part of amino acids to form urea

Question 8

Explain the importance of excretion

Answer 8

toxicity of urea
it helps to maintain the body’s composition of the fluids and prevent toxic substances from building up and killing the body.