Summative Test
1. A
2. A.
3. A
4. D
5. C
6.A
7. D
8. B
b.Draw a labelled diagram of the heart showing the chambers, associated blood vessels and
valves. [4]
Award [1] for each structure clearly drawn and correctly labelled. Schematic
diagrams are acceptable.
1. right and left ventricles – not connected shown larger than atria;
2. right and left atrium – not connected, thinner walls than ventricles;
3. right ventricle has thinner walls than left ventricle / vice versa;
4. atrio-ventricular valves / tricuspid and bicuspid valves – shown between atria and
ventricles;
5. aorta and pulmonary artery – shown leaving the appropriate ventricle with semilunar
valves shown;
6. pulmonary vein and vena cava – shown entering appropriate atrium; [4 max]
Vessels must join unambiguously to correct chamber
c.Describe the relationship between the structure and function of blood vessels. [6]
1. arteries carry blood under high pressure;
2. Arteries have a thicker elastic wall with a narrower lumen;
3. Arteries have muscles that control pressure and help move the blood;
4. Veins carry blood under lower pressure;
5. Veins have thin walls with less elastic tissue, less muscle and wider lumen
than arteries;
6. Veins have valves to prevent back flow;
7. capillaries have walls which are one cell thick;
8. capillaries’ thin walls allow easy diffusion across their wall / ultrafiltration;
d. Draw a labelled diagram to show the human ventilation system. (4)
Award [1] for each structure clearly drawn and correctly labelled.
1.
2.
3.
4.
5.
6.
7.
8.
9.
trachea;
bronchi;
bronchioles;
lungs;
alveoli — shown enlarged as inset;
diaphragm;
intercostal muscles;
abdominal (wall) muscles;
Award [3 max] for diagrams that do not show correct connections
or proportions.4 max
e) List the characteristics of alveoli that permit efficient gas exchange. (4)
1.
2.
3.
4.
5.
6.
large surface area (to lung);
single cell wall layer with elastic properties;
moist lining;
dense network of capillaries;
single cell wall to capillary;
single cell wall layers of capillary and alveoli provide a short distance for gases to travel via
diffusion;
5 max
11. the pressure of a single gas in the mixture as if that gas alone
occupied the container / the
pressure exerted by a single gas in
a mixture of gases;
12.
Diagrams are acceptable provided they are adequately annotated.
1. The initial uptake of one oxygen molecule by hemoglobin
facilitates the further uptake
of
oxygen molecules, because hemoglobin has an increasing affinity
for oxygen as it bonds to
more oxygens / and vice versa;
2. The Oxygen Dissociation Curve (ODC) shows how the saturation of hemoglobin with
oxygen
varies with partial pressure of oxygen , the dissociation curve for (oxy)hemoglobin is
S or sigmoid-shaped;
3. The low partial pressure of oxygen on the curve of the ODC corresponds to the situation in the
tissue;
4. When partial pressure of oxygen is low, like in the respiring tissues/ cells, oxygen is released;
5. The high partial pressure of oxygen on the curve of the ODC corresponds to the situation in the
lungs;
6. When partial pressure of oxygen is high, like in the lungs, oxygen taken up by hemoglobin;
7. Bohr effect occurs when there is lower pH, caused by an increased carbon dioxide and
an
increased lactic acid;
8. The presence of CO2 shifts the curve to the right;
9. This shift means that oxygen will more readily release from hemoglobin to (respiring) tissue;
13.
1.
2.
3.
4.
5.
Carbon dioxide is carried in three forms in the blood;
First, carbon dioxide can be dissolved in the blood / plasma;
Second, carbon dioxide is carried as dissociated carbonic acid / H2CO3 / H+H2 CO3–;
Third, carbon dioxide is carried as carbaminohemoglobin / bound to hemoglobin;
There is carbonic anhydrase enzyme found in red blood cells / erythrocytes which acts on
H2O and Carbon dioxide;
6. Carbonic anhydrase speeds up production of hydrogen carbonate / bicarbonate / H CO3–
from carbon dioxide and water inside the red blood cell. Once carbonate / bicarbonate / H
CO3– is produced is leave the cell via facilitated diffusion;
7. The chloride shift is the movement of chloride ions into red
blood cell and occurs in the
erythrocyte to balance movement of hydrogen carbonate / bicarbonate / H CO3– ion
movement out of the cell;
14
(b)
(a)0 m/at sea level/in Copenhagen and hypoxia
1
correct calculation;
decreases by 28.57% (allow 28.6%)
2
(c)
1. at altitude 5260 m and normoxia there is greatest power output
per kilogram of body
mass;
2. altitude has little effect as the values for 0 m normoxia and
5260 m normoxia are very
similar / normoxia is the (more)
important factor (at both altitudes);
3. O2 levels are significant as values for 0 m hypoxia and 5260 m
hypoxia are very
similar/much lower than for normoxia;
4. O2 levels are more significant than altitude in allowing for
greater power out (per kg
body mass);
2 max
(d)
1. more hemoglobin permits the carrying of more O2 / greater
carrying capacity of O2 /
OWTTE;
2. body acclimatizes to hypoxia/lower O2 partial pressure/concentration;
1 max
(e)
1. lung capacity can increase so that O2 intake becomes more efficient
per breath;
2. heart rate can increase so that the available O2 is circulated around
the body more
quickly to counter the reduced O2 availability;
3. increased number of red blood cells allow greater carrying capacity
(greater amount of
hemoglobin);
4. muscles produce more myoglobin to bind more O2;
5. Accept any other valid adaptations.
2 max
[8]