, 2
1 The pupil is part of the human eye.
Pupil
Iris
A student investigates the effect of changing the light level on pupil diameter. The
student uses a lamp with adjustable brightness, measured in lumens.
The maximum brightness of the lamp is 1200 lumens (100%).
Table 1.1 shows the data the student records.
Table 1.1
Light level Light brightness Distance between Pupil diameter
(%) (lumens) lamp and eye (m) (mm)
80 1.5 4
40 480 1.5 6
20 240 1.5 8
(a) Complete Table 1.2 to identify the variables in the investigation.
Put one tick (✓) in each row to show whether the variable is the dependent variable, the
independent variable or neither.
Table 1.2
Dependent Independen Neither
variable t variable
Distance between lamp and eye (m)
Light brightness (lumens)
Pupil diameter (mm)
[2]
© OCR 2025
, 3
(b) Suggest one other variable not included in Table 1.2 that should be controlled.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(c) Calculate the number of lumens equivalent to a light level of 80%.
Use the data in Table 1.1.
Number of lumens equivalent to a light level of 80% = ............................................ lumens [2]
(d) The student measures the pupil diameter by holding a ruler against the person’s eye.
Suggest a safer way to measure the pupil diameter.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(e) The student predicts that if a light brightness of 1200 lumens is tested, the pupil diameter will be
approximately 2 mm.
Explain why the student is correct.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ............................................................................................................................................................. [3]
© OCR 2025 Turn over
, 4
2 The diagram shows a living plant growing in a bottle garden.
The bottle garden is a small but complete ecosystem.
Bung
Bottle Air
Condensation
Plant leaves
(drops of water)
Plant stem
Plant roots Moist soil
Stones
(a) Which part of the bottle garden ecosystem is biotic?
Tick (✓) one box.
Condensation
Plant
Soil water
Stones
[1]
(b) Explain why the air in the bottle is an abiotic part of the ecosystem.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(c) The bottle allows light to pass through it.
Explain why this is essential for the plant to survive.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
© OCR 2025
1 The pupil is part of the human eye.
Pupil
Iris
A student investigates the effect of changing the light level on pupil diameter. The
student uses a lamp with adjustable brightness, measured in lumens.
The maximum brightness of the lamp is 1200 lumens (100%).
Table 1.1 shows the data the student records.
Table 1.1
Light level Light brightness Distance between Pupil diameter
(%) (lumens) lamp and eye (m) (mm)
80 1.5 4
40 480 1.5 6
20 240 1.5 8
(a) Complete Table 1.2 to identify the variables in the investigation.
Put one tick (✓) in each row to show whether the variable is the dependent variable, the
independent variable or neither.
Table 1.2
Dependent Independen Neither
variable t variable
Distance between lamp and eye (m)
Light brightness (lumens)
Pupil diameter (mm)
[2]
© OCR 2025
, 3
(b) Suggest one other variable not included in Table 1.2 that should be controlled.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(c) Calculate the number of lumens equivalent to a light level of 80%.
Use the data in Table 1.1.
Number of lumens equivalent to a light level of 80% = ............................................ lumens [2]
(d) The student measures the pupil diameter by holding a ruler against the person’s eye.
Suggest a safer way to measure the pupil diameter.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(e) The student predicts that if a light brightness of 1200 lumens is tested, the pupil diameter will be
approximately 2 mm.
Explain why the student is correct.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ............................................................................................................................................................. [3]
© OCR 2025 Turn over
, 4
2 The diagram shows a living plant growing in a bottle garden.
The bottle garden is a small but complete ecosystem.
Bung
Bottle Air
Condensation
Plant leaves
(drops of water)
Plant stem
Plant roots Moist soil
Stones
(a) Which part of the bottle garden ecosystem is biotic?
Tick (✓) one box.
Condensation
Plant
Soil water
Stones
[1]
(b) Explain why the air in the bottle is an abiotic part of the ecosystem.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
(c) The bottle allows light to pass through it.
Explain why this is essential for the plant to survive.
..........................................................................................................................................................
. ............................................................................................................................................................. [1]
© OCR 2025
