mass transprot

Question 1

Explain how water from tissue fluid is returned to the circulatory system.

Answer 1

1. (Plasma) proteins remain;
   2.Reduces water potential (of blood);
2. Water moves (to blood) by osmosis;
3. Returns (to blood) by lymphatic system;

Question 2

Describe two precautions the student should take when clearing away after
the dissection.

Answer 2

dispose in a separate bag
disinfect surfaces

Question 3

Explain how an arteriole can reduce the blood flow into capillaries.

Answer 3

1. Muscle contracts;
2. Constricts/narrows arteriole/lumen;

Question 4

Tick (✓) one box next to the blood vessel carrying blood at the lowest
blood pressure.

Capillary

Pulmonary vein

Renal vein

Vena cava

Answer 4

vena cava

Question 5

Describe and explain the effect of increasing carbon dioxide concentration
on the dissociation of oxyhaemoglobin.

Answer 5

lowers pH
Chang tertiary structure lowering affinity so more unloading

Question 6

explain how the seal’s myoglobin
dissociation curve shows the seal is adapted for diving.

Answer 6

High(er) affinity for O2
Allows (aerobic) respiration when diving/at low(er) pO2

Question 7

how does the heart maintains a unidirectional flow of blood.

Answer 7

Pressure in (left) atrium is higher than in ventricle/B causing valve to open;
Pressure in (left) ventricle/B is higher than in atrium causing valve to close;

Question 8

Binding of one molecule of oxygen to haemoglobin makes it easier for a
second oxygen molecule to bind.

Answer 8

Binding of first oxygen changes tertiary / quaternary (structure) of haemoglobin;
Creates / leads to / uncovers second / another binding site