By what mechanism does gas exchange across the lung occur? a. ...

[Cooldude101]

By what mechanism does gas exchange across the lung occur?
 
  a. Active transport
  b. Facilitated diffusion
  c. Facilitated transport
  d. Simple diffusion

Question 2

Developmental morphogenesis of the human respiratory system can be categorized into:
 
  a. three periods.
  b. five stages.
  c. 6 weeks.
  d. 40 weeks.

[raenoj]

Answer to Question 1

ANS: D
This close match of gas and blood across a large but extremely thin blood-gas barrier membrane enables efficient gas exchange to occur by simple diffusion.

Answer to Question 2

ANS: B
Figure 9-1 shows the various stages of lung development, and Table 8-1 summarizes the major developmental events in each phase.

[Cooldude101]

TYSM

[aliotak]

Excellent