IB Biology HL 3.1.15 Ventilation and gas exchange Question Bank

a. increased (cellular) respiration can increase $\mathrm{CO}_{2}$ levels in blood

OR

anaerobic (cellular) respiration produces lactic acid;

b. due to exercise/lack of oxygen;

c. (aqueous) carbon dioxide reacts to form carbonic acid $/ \mathrm{H}^{+}$ions (and $\mathrm{HCO}_{3}{ }^{-}$ions) OR

increased $\mathrm{CO}_{2}$ levels in blood cause a decrease in pH / acidosis

OR

lactic acid in blood can release $\mathrm{H}^{+}$ions / can cause a decrease in pH /acidosis;

d. in the presence of carbonic anhydrase (enzyme);

e. chemoreceptors detect levels of carbon dioxide (in the blood)

OR

chemoreceptors monitor (blood) $\mathrm{pH} / \mathrm{H}^{+}$(in blood);

f. (chemoreceptors) found in aorta/carotid arteries;

g. (chemosensors/chemoreceptors) send information to respiratory centre in brain OR

to the medulla/brainstem;

h. (medulla) sends nervous impulses to the external intercostal muscles;

i. (medulla) sends nervous impulses to the diaphragm;

j. through intercostal/phrenic nerve;

k. increasing breathing/ventilation rate;

I. increasing volume of the lungs (during inhalation)/ increasing depth of breathing;

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