section 3 (2) explain why the removal of wastes is essential for continued metabolic activity

Question 1

What are some examples of wastes that need to be removed?

Answer 1

• carbon dioxide
• salts
• excess water
• nitrogenous wastes

Question 2

Why must wastes be removed from the body?

Answer 2

• can be toxic to cells

- inhibit enzyme function, hence interfering with normal metabolic activity and homeostasis

Question 3

What are 3 examples of wastes and their impacts?

Answer 3

• CO2; lowers blood pH as bicarbonate ions
• Urea: can build up to toxic levels and poison cells
• Excess mineral salts: effect cell osmotic pressure and hence metabolic efficiency

Question 4

How are CO2, Urea and Excess mineral salts excreted respectively?

Answer 4

• CO2; excreted by lungs
• Urea: excreted by kidneys
• Excess mineral salts: excreted by kidneys and sweat glands