For gas exchange to be efficient, the respiratory membrane must be
a. 0.5 to 1 micrometer thick
b. between 5 and 6 micrometers thick
c. at least 3 micrometers thick
d. the thickness of the respiratory membrane is not important in the efficiency of gas exchange.

A- 0.5 to 1 micrometer thick

Explanation:

During gaseous exchange, the oxygen moves through the respiratory membrane into the blood and the carbon dioxide travels through the respiratory membrane out of the blood. The thickness of the respiratory membrane should be about 0.6 micrometers. A thicker membrane would result in slower and decreased gaseous exchange.

a. as the temperature increases, the kinetic energy of the gas molecules increases & the molecules move faster & further away from each other.

b. if you decrease the temperature of a fixed amount of gas at constant pressure, the combined gas law reduces to charles's law. in this case, volume will also decrease.