The partial pressure of co2 is highest in and lowest in a. venous blood, inspired air b. venous blood, alveoli c. arterial blood, expired air d. arterial blood, venous blood

B) venous blood and aveolar

Explanation:

Partial pressure of carbon dioxide in the aveolar is the lowest, it is 40mmHg (millimetre mecury ) while the partial of carbon dioxide in venous blood is the highest at 45 to 50 mmHg (millimetre mecury)

answer; (phospholipid);

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

read more on -