CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
Exam-style questions and sample answers have been written by the authors. In examinations, the way marks are awarded
may be different.
References to assessment and/or assessment preparation are the publisher's interpretation of the syllabus requirements and may not fully
reflect the approach of Cambridge Assessment International Education.
Name Date
End-of-chapter 12 test
1 Paramedics can examine an unconscious patient by shining a bright light into
their eye.
They then look to see if there is any change in the size of the iris (Figure 12.1).
Figure 12.1
a Explain why the change in the size of the iris is described as a reflex action.
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________ [2]
b Identify the order of structures in the reflex arc that causes this response.
Choose and circle the answer you consider correct.
A retina, sensory neurone, brain, motor neurone, iris
B retina, motor neurone, brain, sensory neurone, iris
C iris, motor neurone, brain, sensory neurone, iris
1
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
D iris, sensory neurone, brain, motor neurone, iris [1]
2
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
c A patient’s pupil did not change in size during such an examination. Suggest
one reason why.
_________________________________________________________________________
_________________________________________________________________________ [1]
[Total: 4]
2 a Myopia is a common visual defect. It is caused by a problem with the
refraction of light inside the eye. Identify which diagram in Figure 12.2
illustrates how spectacles are used to correct myopia.
Figure 12.2
[1]
b Pseudomyopia is a temporary condition caused by prolonged focus on near
objects, such as
a computer screen. In pseudomyopia, the ciliary muscles do not relax.
Describe and explain
the effect of pseudomyopia on a person’s vision.
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________ [3]
c Laser eye surgery is one possible treatment for accommodation defects. In
this process,
a laser is used to heat and reshape the cornea.
i Suggest how the reshaping of the cornea could improve a person’s vision.
3
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
_______________________________________________________________________
_______________________________________________________________________ [2]
4
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
ii Concerns about the expense and safety of laser eye surgery have led to a
decreasing number of people opting for the procedure in recent years.
Table 12.1 shows the number of people treated using this method in the
United States in 2009, 2013 and 2017.
Year 2009 2013 2017
Number of people treated 1.4 × 106 6.2 × 105 6.0 × 105
Table 12.1
Calculate the percentage decrease in the number of people treated by laser
eye surgery
between 2009 and 2017.
_____
[2]
[Total: 8]
1 A group of learners investigated the concept of geotropism in relation to root
growth in germinating pea seedlings.
They arranged their equipment as shown and used a piece of apparatus called
a clinostat.
This suspended and slowly rotated the seedlings over several days (Figure
12.3).
Figure 12.3
a Describe and explain one way in which the learners could have improved the
validity of
their investigation.
5
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
_________________________________________________________________________
_________________________________________________________________________ [2]
6
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
CAMBRIDGE IGCSE™ BIOLOGY: END-OF-CHAPTER TEST 12
b Describe how a control should be set up for this experiment, and the
observations you would predict seeing.
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________ [2]
c Explain why the roots of the seedlings grew horizontally in the experiment
shown in
Figure 12.3.
_________________________________________________________________________
_________________________________________________________________________ [2]
d Auxin can be used as a weed killer to increase yield in crop farming. Some
people are concerned by the widespread use of artificial plant hormones in
this way.
Suggest why.
_________________________________________________________________________
_________________________________________________________________________ [2]
[Total: 8]
[Test total: 20]
END OF TEST
7
Cambridge IGCSE™ Biology – Martindill © Cambridge University Press 2021
