A Level Biology A
H420/01 Biological Processes
Question Set 24
Multiple Choice Questions
1 A student counted stomata on a leaf using a light microscope. The image below shows the
stomata that were visible.
The image magnification is ×60.
Which of the options, A to D, is the correct stomatal density of this leaf?
A 7.50 stomata mm–2
B 0.13 stomata mm–2
C 2428 stomata mm–2
D 0.21 stomata mm–2
Your answer
[1]
2 Bony fish absorb dissolved oxygen from the water using gills. Water is passed through the
buccal cavity and over the gill lamellae. The oxygen saturation of the blood and water
changes as the water passes over the gills.
Which of the statements, A to D, correctly describes the way oxygen is transferred into the
bloodat the gills?
A Blood and water flow in a concurrent system with a constant concentration
gradient between them.
B Blood and water flow in a countercurrent system with a constant
concentration g r a d i e n t b e t w e e n them.
C Blood and water flow in a concurrent system with a greater concentration
gradient between them at the start of the gill lamella.
D Blood and water flow in a countercurrent system with a greater
concentration g r a d i e n t b e t w e e n them at the start of the gill lamella.
Your answer
3
[1]
3 Which of the statements, A to D, correctly describes the process of adhesion?
A attraction of water molecules to the impermeable walls of xylem tissue
B attraction of water molecules to other water molecules in the xylem tissue
C active transport of water molecules into phloem tissue
D attraction of water molecules to other water molecules in the phloem tissue
Your answer
[1]
4 Different sized mammals have different surface area to volume ratios.
The table shows the surface areas and volumes of four different groups of mammals.
Mammal genus Surface area (m2) Volume (m3) S -
Oryctolagus 0.48 2.0 × 10–2 24
Equus 18.26 2.24 8.2
Mus 1.9 × 10–3 7.2 × 10–5 26.4
Rattus 0.32 1.6 × 10–2 20
Which of the options, A to D, is the correct order of surface area to volume ratios for the
different mammals, arranged from the largest to the smallest?
A Oryctolagus, Rattus, Equus, Mus
B Mus, Rattus, Oryctolagus, Equus
C Mus, Oryctolagus, Rattus, Equus
D Equus, Mus, Oryctolagus, Rattus
Your answer
c
[1]
5 Mistletoe is a plant parasite that lives on the stems of other plants. It survives by removing
water and assimilates from the host plant.
The mistletoe binds to the stem of the host plant and grows a specialised root-like tissue
called a haustorium that attaches to different tissues in the stem.
One species of mistletoe, Viscum minimum, contains no chloroplasts.
Which of the options, A to D, explains why V. minimum does not need chloroplasts?
A the haustorium of V. minimum attaches to sieve tube elements
B the haustorium of V. minimum attaches to xylem vessels
C the haustorium of V. minimum attaches to meristem cells
D the haustorium of V. minimum attaches to cambium tissue
Your answer
[1]
6 Which of the following statements, A to D, correctly explains a feature of an efficient
gaseousexchange surface?
A The layers are thin for a short diffusion distance.
B There is a good blood supply, so the system reaches equilibrium quickly.
C There is an increased surface area to reduce surface area to volume ratio.
D Ventilation takes place to reduce concentration gradient of dissolved gases.
Your answer
[1]
7
2 Which of the statements, A to D, applies to transpiration and evaporation?
A It occurs at a faster rate at higher humidity.
B It occurs at a slower rate at greater wind speed.
C It occurs at a slower rate at higher temperature.
D It occurs at the surface of leaves.
Your answer
:
[1]
8 Which of the statements, A to D, explains why diastole follows systole in the mammalian
heart?
A Cardiac muscle is myogenic.
B Cardiac muscle takes a short time to repolarise after being stimulated.
C The aorta is capable of maintaining the pressure generated by the left ventricle.
D The SAN receives impulses from the AVN.
Your answer
3 [1]
9
Peak expiratory flow (PEF) is a measure of the maximum rate at which a person can
exhale.
The graph below shows the typical PEF values for men of different ages and heights.
Which of the following is the percentage increase from the PEF of a 20 year old man of 175
cm to the PEF of a 45 year old man of 183 cm?
A 19.4% 640 570
100 123%
570
B 10.9%
C 12.3%
D 8.1%
Your answer
c
[1]
10
Myoglobin is a protein found in muscle. Myoglobin has a very high affinity for
oxygen at mostpartial pressures of oxygen.
The figure below shows dissociation curves for
• adult haemoglobin
• fetal haemoglobin
• myoglobin.
Which of the following rows, A to D, shows the correct labels for the lines on the graph?
X Y Z
A myoglobin fetal haemoglobin adult haemoglobin
B fetal haemoglobin adult haemoglobin myoglobin
C adult haemoglobin fetal haemoglobin myoglobin
D myoglobin adult haemoglobin fetal haemoglobin
Your answer
[1]
Total Marks for Question Set 24: 10
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