Gaseous Exchange

Multiple Choice

What is the primary function of haemoglobin in the human body?

• To carry carbon dioxide

• To carry oxygen

• To regulate blood pressure

• To produce energy

Multiple Choice

What is the effect of one molecule of O₂ binding to a haemoglobin subunit?

• It decreases the affinity for oxygen

• It has no effect on the other subunits

• It increases the affinity for oxygen

• It causes the haemoglobin to release carbon dioxide

Multiple Choice

What atom is attached to each porphyrin ring of haem group consist?

• Magnesium

• Zinc

• Iron

• Chlorine

Multiple Choice

What is the chemical equation representing the binding of haemoglobin with oxygen?

• Hb + 4O₂ → HbO₂

• Hb + O₂ → HbO

• Hb + 2O₂ → HbO₂

• Hb + O₂ → HbO₂

Multiple Select

What are the three ways of CO₂ transport from respiring tissues to lungs?

• Dissolved CO₂ in blood plasma

• As bicarbonate ion.

• As carbominohaemoglobin

• Bound to the amino group of hemoglobin.

• Bound to the haem group of haemoglobin

Multiple Choice

What does the oxygen dissociation curve of hemoglobin illustrate about the relationship between oxygen saturation and partial pressure of oxygen (P_O2)?

• It shows a linear relationship

• It shows a parabolic relationship

• It shows a sigmoidal relationship

• It shows no relationship

Multiple Choice

What does the sigmoidal shape of the oxygen dissociation curve indicate about the binding of haemoglobin with oxygen?

• It indicates a linear relationship

• It shows cooperativity in binding

• It suggests no affinity changes

• It represents a constant saturation

Multiple Choice

What happens to the saturation of hemoglobin with oxygen (O₂) at very high partial pressures (P0₂) at the lungs?

• It decreases to 70%

• It remains at 100%

• It increases to 98%

• It becomes zero

Multiple Select

What does the steepest part of the oxygen dissociation curve indicate about the release of O₂ from hemoglobin?

• It indicates a low saturation of hemoglobin

• It indicates the cooperative binding of haemoglobin with O₂

• It indicates a rapid release of O₂

• It indicates a slow release of O₂

Multiple Choice

What is the percentage of oxygen unloaded to tissues during exercise?

• 28%

• 80%

• 70%

• 98%

Multiple Choice

What is the percentage of oxygen unloaded to tissues at rest?

• 28%

• 80%

• 70%

• 98%

Multiple Choice

What is the primary function of myoglobin in muscle tissue?

• To transport carbon dioxide

• To store oxygen

• To release carbon dioxide

• In charge of gaseous exchange

Multiple Choice

What are the similarities between the oxygen dissociation curves of myoglobin and hemoglobin?

• Both curves show the increase in saturation with O₂ when P_O2 is high

• Both curves show the increase in dissociation with O₂ when P_O2 is low

• Both curves are identical in shape

• Both curves are affected by pH levels

Multiple Select

Stomata close during the ___?

• day
• hot and dry day

• noon

• night

Poll

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