Question 1

The graph shows the oxygen dissociation curves for haemoglobin of animals that live at high altitude and animals that live at low altitude.

What explains the oxygen dissociation curve at high altitude?

  A  

haemoglobin has a higher affinity for oxygen


  B  

haemoglobin releases oxygen more readily

  C  

the change in partial pressure of carbon dioxide causes a Bohr effect

  D  

the decrease in percentage of carbon dioxide causes the curve to shift to the left

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Question 2

Haemoglobin can bind to carbon dioxide, carbon monoxide, and oxygen.

Which statement about the binding sites of haemoglobin is correct?

  A  

carbon dioxide and carbon monoxide bind to one site, oxygen binds to a different site

  B  

carbon dioxide and oxygen bind to one site, carbon monoxide binds to a different site

  C  

carbon monoxide and oxygen bind to one site, carbon dioxide binds to a different site

  D  

carbon monoxide, oxygen and carbon dioxide all bind to different sites

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Question 3

An increase in carbon dioxide in human blood shifts the oxyhaemoglobin dissociation curve to the right.

What is the explanation for this effect?

  A  

an increase in carbon dioxide concentration increases the ventilation rate

  B  

carbon dioxide is more soluble than oxygen and displaces it

  C  

diffusion of carbon dioxide between the alveoli and the blood is more rapid

  D  

increasing the H+ concentration decreases haemoglobin affinity for oxygen

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Question 4

Which statement describes the Bohr effect?

  A  

in high partial pressure of oxygen and high partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen increases


  B  

in high partial pressure of oxygen and low partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen decreases

  C  

in low partial pressure of oxygen and high partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen decreases

  D  

in low partial pressure of oxygen and low partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen is unchanged

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Question 5

What is the reason for an increase in red blood cells in humans at high altitudes?

  A  

to compensate for the low percentage saturation of haemoglobin


  B  

to enable haemoglobin to unload more oxygen in the tissues by the Bohr effect

  C  

to ensure that haemoglobin is almost 90% saturated when it reaches the tissues

  D  

to increase the number of mitochondria in the blood for ATP production

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Question 6

What is the primary structure of haemoglobin made up of?

  A  

alpha helices

  B  

beta sheets

  C  

polypeptide chains

  D  

haem groups

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Question 7

Which statement best describes cooperative binding in haemoglobin?

  A  

the binding of the first oxygen molecule has no effect on the binding of subsequent oxygen molecules

  B  

the binding of the first oxygen molecule makes it harder for subsequent oxygen molecules to bind

  C  

the binding of the first oxygen molecule makes it easier for subsequent oxygen molecules to bind

  D  

the binding of oxygen molecules is completely independent of other molecules

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Question 8

Why does haemoglobin offload more oxygen into tissues with high metabolism?

  A  

because these tissues have a lower pH

  B  

because these tissues have a higher pH

  C  

because these tissues have a lower temperature

  D  

because these tissues have a higher temperature

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Question 9

What effect does a low pH have on the affinity of haemoglobin for oxygen?

  A  

it increases the affinity

  B  

it decreases the affinity

  C  

it does not affect the affinity

  D  

it reverses the affinity

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Question 10

Haemoglobins with a high affinity for oxygen are characterised by their ability to do what?

  A  

take up oxygen more easily and release it more easily

  B  

take up oxygen more easily but release it less easily

  C  

take up oxygen less easily and release it more easily

  D  

take up oxygen less easily but release it less easily

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