Cambridge International A Level Biology Revision Guide

Cambridge International AS Level Biology
2 The micrograph shows an artery and a vein.
X
Y
Which row correctly identifies and describes the artery and the vein?
180
X Y Description
A artery vein The artery has thick walls and the vein has thin walls.
B artery vein The artery has a thin tunica media while the vein has a thick tunica media.
C vein artery The artery has a thick tunica media while the vein has a thin tunica media.
D vein artery The artery has thin walls and the vein has thick walls.
3 Where is the mammalian heart beat initiated?
A atrioventricular node
B left atrium
C Purkyne tissue
D sinoatrial node [1]
4 What causes the bicuspid valve to close during ventricular systole?
A a greater blood pressure in the left atrium than in the left ventricle
B a greater blood pressure in the left ventricle than in the left atrium
C contraction of muscles in the septum
D contraction of muscles in the valve [1]
5 Construct a table comparing the structure of arteries, veins and capillaries. Include both similarities and
differences, and give reasons for the differences which you describe. [6]
6 Construct a table comparing blood plasma, tissue fluid and lymph. [6]
7 Explain how the structure of haemoglobin enables it to carry out its functions. (You may wish to look back
at Chapter 2 to remind you about the various levels of structure of a protein molecule such as haemoglobin.) [6]
8 The following statements were all made by candidates in examination answers. Explain what is wrong with
each statement.
a Oxyhaemoglobin gradually releases its oxygen as it passes from the lungs to a muscle. [2]
b The strong walls of arteries enable them to pump blood around the body. [2]
c Each red blood cell can combine with eight oxygen atoms. [2]
d Red blood cells have a large surface area so that many oxygen molecules can be attached. [2]
[Total: 8]
[1]