Specialised exchange surfaces

Question 1

Increased surface area

Answer 1

Provides the area needed for exchange and reduces the effect of SA:V

Question 2

Thin layers

Answer 2

Distance substances have to diffuse are short making her process quick and efficient

Question 3

Good blood supply

Answer 3

Good blood supply means substances are constantly delivered to and removed from the exchange surface. This maintains a steep concentration gradient for diffusion.

Question 4

Whats good about Ventilation

Answer 4

Maintains concentration gradient and makes the process more efficient

Question 5

Why do multicellular organisms needs specialised exchange surfaces but single celled organisms do not

Answer 5

Single celled organisms:
have a large SA:V
Are small so demand for oxygen is low
Diffusion alone is adequate

multicellular organisms:
Have a higher demand for oxygen
smaller SA:V
Diffusion would take too long

Question 6

How are the alveoli adapted for gas exchange?

Answer 6

They have a thin squamous epithelium (short diffusion pathway)

the epithelial cells produce a surfactant (reduces surface tension)

Good blood supply to maintain concentration gradient (capillary network)