Quiz 17: WS11.2 answers

Kowloon Tong School (Secondary Section)

F.2 Integrated Science Quiz 17 WS11.2

Words Translation (5 marks)

	Chinese term	English term
1	角膜	Cornea
2	虹膜	Iris
3	瞳孔	Pupil
4	晶狀體	Lens
5	視網膜	Retina

Label the diagrams (15 marks)

Fill in the Blanks (13 marks)

1        (1)Cornea is a colourless layer which protects the eye and allow light to pass through. It also helps to focus light onto the retina.

2        (2)Iris controls the size of the pupil and hence the amount of light entering the eye.

3        (3)Pupil is a hole which allows light to enter the eye. In bright light, it becomes (4)smaller so that less light is allowed to enter the eyes. In (5)dim light, it becomes larger so that more (6)light

can enter the eyes.

4        (7)Lens allows light to pass through. Its thickness can be changed so as to focus light onto the

(8)retina, forming an (9)sharp image.

5        (10)Retina contains light receptors that can detect light and produce signals which are then

travel to the brain through (11)optic nerve.

6        The brain (12)interprets the signals to give us the sense of sight.

7        (13)White protective coat protects the eyeball and give it shape.

Challenging Questions (Bonus 2 marks)

1.      Why is it important for the pupil to become smaller under bright light?

To reduce the amount of light entering the eyes which may damage the retina.

2.      How can the eye focus the light from the objects at different distances onto the retina?

By changing the thickness of the lens.