Animal Adaptations For Their Environment

Question 1

Different types of haemoglobin

Haemoglobin is a quaternary protein made up of four globin polypeptides and four haem groups

The structure of haem is identical in all types of haemoglobin but the globin chains can differ substantially between species

The globin polypeptides determine the precise properties of haemoglobin

Haemoglobin types vary in their oxygen-binding properties, meaning that they

Answer 1

bind to and release oxygen in different conditions

Question 2

Environmental factors can have a major impact on the evolution of haemoglobin within a species

Question 3

Effects of altitude
The partial pressure of oxygen in the air is lower at

Answer 3

higher altitudes

Question 4

Species living at high altitudes have haemoglobin that is adapted to these conditions, e.g.
Llamas have haemoglobin that

Answer 4

binds much more readily to oxygen

Question 5

Llamas have haemoglobin that binds much more readily to oxygen

how is this beneficial

Answer 5

This is beneficial as it allows them to obtain a sufficient level of oxygen saturation in their blood when the partial pressure of oxygen (pO2) in the air is low

Question 6

The haemoglobin of a developing foetus has a

Answer 6

higher affinity for oxygen than adult haemoglobin

Question 7

The haemoglobin of a developing foetus has a higher affinity for oxygen than adult haemoglobin
This is vital as it allows a foetus to

Answer 7

obtain oxygen from its mother’s blood at the placenta
Fetal haemoglobin can bind to oxygen at low pO2
At this low pO2 the mother’s haemoglobin is dissociating with oxygen

Question 8

On a dissociation curve graph, the curve for foetal heamoglobin shifts to the ………..of that for adult haemoglobin

this means

Answer 8

left

This means that at any given partial pressure of oxygen, foetal haemoglobin has a higher percentage saturation than adult haemoglobin

Question 9

After birth, a baby begins to produce adult haemoglobin which gradually replaces foetal haemoglobin
This is important for the

Answer 9

easy release of oxygen in the respiring tissues of a more metabolically active individual

Question 10

You may be shown the oxygen dissociation curves of different types of haemoglobin and asked to explain how they are adapted to the environment the animal is living in. Remember that the curve furthest to the left represents the haemoglobin with the highest affinity for oxygen.