Excretion (Cambridge O Level Biology)

Excretion is the removal of toxic substances or substances in excess, from the body. 

Excess water is excreted from the lungs and the kidneys.

State the name of one other substance that is excreted from

• • The lungs
  • The kidneys. 

The volume and concentration of urine varies with changing conditions.

Table 1 shows three changing conditions.

Write increase or decrease in each of the boxes in Table 1 to show how each change affects the volume and the concentration of urine.

Table 1

changing condition	volume of urine	concentration of urine
increase in water intake
increase in temperature
increase in exercise