F2 IS 2nd term QZ 10 (11.2) ans

Word Translation (8 marks)

i    Write down the English terms of the following Chinese terms:

	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
6	黃點	Yellow spot
7	盲點	Blind spot
8	視神經	Optic nerve

Label the diagrams (15 marks)

1. Eye lid                                      2. Eye lashes

3. Cornea                                     4. Pupil

5. Iris                                           6. White protective layer

7. Cornea                                     8. Iris

9. Pupil                                        10. Lens

11. Retina                                    12. White protective layer

13. Yellow spot                            14. Blind spot

14. Optic nerve

Fill in the Blanks (12 marks)

1        (1)Lens 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)Pupil is a hole which allows light to enter the eye. In bright light, it becomes

(3)smaller so that less light is allowed to enter the eyes. In (4)dim light,

it becomes larger so that more (5)light can enter the eyes. Is size is controlled by (6)iris.

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

(8)retina, which produces and send signals to the brain through (9)optic nerve.

4        (10)Yellow spot is the part of the retina which contains most light receptors and gives

clearest vision. However, (11)blind spot does not contain any light receptors and gives no vision even an image is formed on it.

5        (12)White protective layer 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?

This can reduce the amounts of light entering the eye so as to

prevent the retina from being damaged by the strong light.

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

The lens changes its thickness so that the light from the objects at different

distances can be focused and form sharp images on the retina.