2.70 Excretion in plants and animals

Question 1

What are the plants waste products?

Answer 1

Water
Carbon dioxide
Oxygen

Question 2

How does the light intensity affect the substances excreted?

Answer 2

-During the day when there is more sunlight, more photosynthesis happens. Leading to excess oxygen needing to be excreted
-During night, there is no sunlight and only respiration happens which uses up oxygen but creates excess carbon dioxide which needs to be excreted

Question 3

How is water excreted in plants?

Answer 3

Through transpiration

Question 4

What are the humans waste products?

Answer 4

Water
Carbon dioxide
Urea

Question 5

What negative effects could build up of waste products cause in humans?

Answer 5

They can be toxic, carbon dioxide raising pH levels
Body fluids can become more concentrated affecting osmosis
Uses up storage

Question 6

What are the human excretory organs?

Answer 6

The kidneys
The lungs
Skin

Question 7

What do the kidneys do in excretion?

Answer 7

They excrete urea, water and excess salts through urine

Question 8

What do the lungs do in excretion?

Answer 8

They excrete water and carbon dioxide through exhaling, water in the form of vapour

Question 9

What does the skin do in excretion?

Answer 9

The skin excretes water, excess mineral ions and a little urea through sweating