specialised exchange surfaces

Question 1

increased surface area

Answer 1

• a larger surface area allows for more exchange to occur, this overcomes the lack of SA :V ratio of larger organisms.

Question 2

thin layers

Answer 2

• shorter diffusion distance for substances, making the process fast and efficient.
• example : alveoli of the lungs

Question 3

good blood supply

Answer 3

• the steeper the concentration gradient , the faster diffusion takes place.
• ensures substances are constantly delivered to and removed from the exchange surface.
• maintains a steep concentration gradient for diffusion
  E.g. : alveoli, gills of fish

Question 4

ventilation to maintain diffusion gradient

Answer 4

• for gases, a ventilation system also helps maintain concentration gradients and makes the process more efficient