Download Answers for support worksheet – Option H

Cambridge Biology for the IB Diploma
Answers for support worksheet – Option H
1
2
a
The diagram includes a duct so the secretion does not enter the bloodstream directly and
therefore the gland is an exocrine gland.
(1)
b
any three from:
nucleoli for the production of RNA
rER for protein synthesis
Golgi apparatus for processing protein
mitochondria to provide energy
vesicles for storage of product to be secreted
(6)
c
the small intestine (ileum)
(1)
d
pancreatic amylase – digestion of starch to maltose and maltose to glucose
(1)
pancreatic lipase – digestion of lipids
(1)
trypsinogen – digestion of polypeptides and dipeptides
(1)
a
carbohydrate – reserve of glucose as glycogen, maintains constant blood level
calciferol – vitamin D, prevents rickets in children
retinol – needed for normal vision
iron – used to manufacture red blood cells
b
3
(4)
The liver synthesizes plasma proteins (blood proteins). These help maintain the osmotic
potential of the blood (and have a variety of other functions).
The liver also synthesizes cholesterol, which is a component of cell membranes.
(2)
c
A = hepatic vein, B = hepatic artery, C = hepatic portal vein
(3)
d
i
Kupffer cells
(1)
ii
The heme group is split into iron and bile pigment; globins are converted to amino
acids and reused.
(3)
a
At high partial pressures of oxygen, hemoglobin becomes saturated with oxygen. As the
partial pressure of oxygen falls, most of the oxygen remains bound to hemoglobin. In
areas where the partial pressure of oxygen is low, oxyhemoglobin dissociates and oxygen
is released to the tissues.
(3)
b
Myoglobin has a higher affinity for oxygen than hemoglobin. It binds to oxygen at a
lower partial pressure of oxygen and does not release it until the partial pressure has
fallen very low.
(2)
To the left of the curve for adult hemoglobin.
(1)
c
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Cambridge Biology for the IB Diploma
d
The partial pressure of oxygen in mud is very low and so would be insufficient to
pass into the larvae by diffusion. Hemoglobin enables the larvae to pick up the oxygen
that is present.
(2)
e
Carbon dioxide lowers the pH of the blood and this is sensed by the medulla, which
stimulates the breathing response. Lowering the carbon dioxide content of the blood
reduces the stimulus to breathe, and the diver can remain underwater for longer.
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(3)
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