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JAN-FEB EXTREME- SCIENCE
Section 1
Read each question carefully. Choose the most suitable answer.
1. What colour is an object that absorbs light of all wavelengths?
A. Red.
B. Yellow.
C. Black
D. White.
2. Which of the following is not true about light?
A. Light is a form of energy.
B. Light can be absorbed by materials.
C. Light travels slower than sound.
D. Light travels in waves.
3. What are the primary colours of light?
A. Yellow, red and blue.
B. Yellow, red and green.
C. Yellow, green and blue.
D. Red, green and blue.
4. An apple looks red because they _______________.
A. reflect white light.
B. absorb all light except red.
C. turn ultraviolet light into red light.
D. absorb red light and reflect all other light.
5. The bending of light is called ______________.
A. reflection.
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B. refraction.
C. translucent.
D. transparent.
Section 2
Answer the questions in the spaces provided.
6. The diagram below is a cross-section of an eye. Answer the following questions based
on the diagram.
a. Label the parts of the eye in the diagram.
A: _____________________________________________________
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B: _____________________________________________________
C: _____________________________________________________
D: _____________________________________________________
E: _____________________________________________________
F: _____________________________________________________
G: _____________________________________________________
H: _____________________________________________________
b. Which structure helps focus the light on to the retina?
______________________________________________________________________________
______________________________________________________________________________
c. Differentiate the function of part B and part G.
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______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
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d. What happens if the eyeball is elongated and in the shape of a rugby ball? Explain the
condition and how it can be rectified.
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______________________________________________________________________________
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Answer Key
Section 1
1. C. Black.
Tip: A black object scatters little light, and absorbs light at all visual wavelengths; a green object
scatters more green light than other colours, which it absorbs more.
2. C. Light travels slower than sound.
Tip: Light waves travel really fast at 3,000,000,00 meters every second. They do not need
to travel through a medium like air.
3. D. Red, green and blue.
Tip: Red, green, and blue are the primary colors of light—they can be combined in different
proportions to make all other colors.
4. B. absorb all light except red.
Tip: An apple appears to be red because it reflects the red wavelength while absorbing all
the other colors.
5. B. Refraction.
Tip: The refraction occurs at the boundary and is caused by a change in the speed of the
light wave upon crossing the boundary.
Section 2
6.
a. A: Sclera
B: Cornea
C: Pupil
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D: Lens
E: Iris
F: Ciliary body
G: Retina
H: Optic nerve
b. The lens. It is the transparent structure suspended behind the iris that helps to focus
light on the retina.
c. Part B is the cornea. The cornea acts as the eye's outermost lens. It functions like a
window that controls and focuses the entry of light into the eye. The cornea contributes
between 65-75 percent of the eye's total focusing power. Part G is the retina. The
cornea and the lens help to focus the light rays onto the back of the eye which is the
retina. The cells in the retina absorb and convert the light to electrochemical impulses
which are transferred along the optic nerve and then to the brain.
d. Nearsightedness, also known as myopia, is a common type of refractive error where
close objects appear clearly, but distant objects appear blurry. Nearsightedness
develops in eyes that focus images in front of the retina instead of on the retina, which
results in blurred vision. This occurs when the eyeball becomes too long and prevents
incoming light from focusing directly on the retina. It may also be caused by an abnormal
shape of the cornea or lens.
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