definition and others idk

Question 1

Excretion

Answer 1

removal from the body of the waste compounds produced during the metabolism of cells

Question 2

Importance of removing nitrogenous and other compounds from body

Answer 2

• Animals do not store protein so excess amino acids are deaminated in the liver to form ammonia which is extremely toxic.
• Ammonia is promptly converted to a safer nitrogenous compound, urea, which is excreted by the kidneys in urine.

Question 3

Function of nephron with reference to ultra-filtration and selective reabsorption in production of urine

Answer 3

• Nephrons filter blood and then reabsorb useful materials from the filtrate before eliminating the remainder as urine

Ultrafiltration – Blood is filtered out of the glomerulus at the Bowman’s capsule to form filtrate

Selective reabsorption – Usable materials are reabsorbed in convoluted tubules (both proximal and distal)