Topic 1 Exchange Surfaces %

Question 1

What depends on the surface area to volume ratio

Answer 1

How easily stuff moved between organism and its environment

Question 2

What happens to surface area to volume ratio if an organism is large

Answer 2

The larger an organism is the smaller its surface area is compared to its volume

Question 3

Area calculation

Answer 3

Length x width

Question 4

Volume equation

Answer 4

Length X width X height

Question 5

Exchange surface in single celled organisms

Answer 5

Gases and dissolve substances can just diffuse directly into or out of the cell across the cell membrane
because they have a large surface area compared to their volume, so enough substances can be exchanged across the membrane to supply the volume of the cell

Question 6

Exchange surfaces in multicellular organisms

Answer 6

Multicellular organisms have a smaller surface area to the volume
not enough substances can diffuse to supply the entire volume, this means they need some sort of exchange surface for efficient diffusion

Question 7

What are exchange surfaces

Answer 7

Exchange surfaces structures allow enough of the necessary substances to pass the through

Question 8

How have exchange surfaces adapted

Answer 8

Thin membrane so Substances only have a short distance to diffuse
Large surface area so lots Substances can diffuse at once
Exchange surfaces in animals have lots of blood vessels to get stuff in and out of the blood quickly
Gassiest exchange surfaces in animals (alveoli) are often ventilated (air moves in and out)