The eyeIB MYP Biology: Subtopic test

1. 1
   Amara walks from a bright street in Lagos into a dimly lit cinema. For a few moments she can see very little, then her vision gradually improves. When she leaves after the film, the bright sunlight is uncomfortable at first.

   (a)

   Which part of the eye changes size to control how much light enters?

   [1 mark]

   • ACornea
   • BIris
   • CRetina
   • DOptic nerve

   (b)

   What happens to Amara's pupil as she enters the dim cinema?

   [1 mark]

   • AIt gets larger so more light enters
   • BIt gets smaller so less light enters
   • CIt stays the same size because the reflex only works in bright light
   • DIt moves backwards so the lens can focus

   (c)

   Explain how Amara's pupils respond when she leaves the cinema, and why this response is useful.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Kenji is reading a message on his phone, held close to his face. He then looks up to read a road sign on the other side of the street.

   (a)

   Which structure changes shape to focus light onto the retina?

   [1 mark]

   • ACornea
   • BPupil
   • CLens
   • DOptic nerve

   (b)

   Kenji looks up at the distant road sign. What happens in his eye?

   [1 mark]

   • AThe ciliary muscles contract and the lens becomes thicker
   • BThe ciliary muscles contract and the lens becomes thinner
   • CThe ciliary muscles relax and the lens becomes thicker
   • DThe ciliary muscles relax and the lens becomes thinner

   (c)

   Explain how the eye changes so that Kenji can focus on his phone.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A class investigates the pupil reflex. One student sits in a room where the light intensity can be changed. After one minute of adjusting to each light level, a partner holds a ruler beside the student's eye and estimates the pupil diameter. The results were: 7.5 mm at 10 lux, 5.0 mm at 100 lux, 3.0 mm at 1000 lux and 2.0 mm at 10 000 lux.

   (a)

   Describe the trend in the results and use the data to support your answer.

   [3 marks]

   (b)

   Evaluate the method used in this investigation and suggest two improvements.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A school in Dubai runs an eye screening day for Year 9 students. Layla can read her book clearly but cannot read the whiteboard from the back of the room. Her classmate Omar can read the whiteboard but has to hold his book at arm's length to read it. The school's health committee must also decide whether to pay for glasses for every student who needs them.

   (a)

   Explain what causes each student's sight problem and how each could be corrected.

   [6 marks]

   (b)

   Discuss whether the school should pay for glasses for every student who needs them. Reach a justified conclusion.

   [6 marks]

   Total for question 4: 12 marks

End of questions