Everyday Science MCQs – Set 8
Practice 20 important Everyday Science MCQs covering human biology, nutrition, chemistry, physics, plants, weather, earth science and astronomy. Click Show Correct Answer to reveal the answer with a short explanation.
1. Which part of the human eye focuses light onto the retina?
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Correct Answer: B. Lens
The lens changes its shape to focus incoming light onto the retina, helping produce a clear image.
The lens changes its shape to focus incoming light onto the retina, helping produce a clear image.
2. Which blood vessels carry blood away from the heart?
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Correct Answer: B. Arteries
Arteries carry blood away from the heart. Most arteries carry oxygen-rich blood, although the pulmonary arteries are an important exception.
Arteries carry blood away from the heart. Most arteries carry oxygen-rich blood, although the pulmonary arteries are an important exception.
3. Which blood vessels are the main sites for exchange of gases and nutrients between blood and tissues?
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Correct Answer: C. Capillaries
Capillaries have very thin walls that allow oxygen, nutrients and waste products to move between blood and surrounding tissues.
Capillaries have very thin walls that allow oxygen, nutrients and waste products to move between blood and surrounding tissues.
4. Which vitamin is naturally produced in the human body when skin is exposed to sunlight?
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Correct Answer: C. Vitamin D
Exposure to ultraviolet B radiation helps the skin produce vitamin D, which is important for calcium metabolism and bone health.
Exposure to ultraviolet B radiation helps the skin produce vitamin D, which is important for calcium metabolism and bone health.
5. Which part of the brain is mainly responsible for controlling breathing and heartbeat?
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Correct Answer: B. Medulla oblongata
The medulla oblongata contains centres that help regulate vital involuntary functions such as breathing and heart rate.
The medulla oblongata contains centres that help regulate vital involuntary functions such as breathing and heart rate.
6. What is the chemical formula of common table salt?
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Correct Answer: A. NaCl
Table salt is mainly sodium chloride, whose chemical formula is NaCl.
Table salt is mainly sodium chloride, whose chemical formula is NaCl.
7. Which gas is the main component of natural gas?
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Correct Answer: A. Methane
Natural gas consists mainly of methane, although it can contain smaller amounts of other gases.
Natural gas consists mainly of methane, although it can contain smaller amounts of other gases.
8. Which substance turns blue litmus paper red?
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Correct Answer: A. An acid
Acids change blue litmus paper to red, while bases generally change red litmus paper to blue.
Acids change blue litmus paper to red, while bases generally change red litmus paper to blue.
9. Which gas is poisonous because it reduces the blood's ability to carry oxygen?
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Correct Answer: A. Carbon monoxide
Carbon monoxide binds strongly to haemoglobin, reducing the blood's ability to transport oxygen to body tissues.
Carbon monoxide binds strongly to haemoglobin, reducing the blood's ability to transport oxygen to body tissues.
10. Which process separates a mixture based on differences in the boiling points of its components?
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Correct Answer: B. Distillation
Distillation separates substances by heating a mixture and then condensing vapours based on differences in boiling points.
Distillation separates substances by heating a mixture and then condensing vapours based on differences in boiling points.
11. What happens to the pressure of a gas when its volume is reduced while temperature remains constant?
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Correct Answer: B. It increases
At constant temperature, reducing the volume of a gas generally increases its pressure because the particles collide with the container walls more frequently.
At constant temperature, reducing the volume of a gas generally increases its pressure because the particles collide with the container walls more frequently.
12. Which instrument is used to measure temperature?
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Correct Answer: A. Thermometer
A thermometer measures temperature using a physical property that changes predictably with temperature.
A thermometer measures temperature using a physical property that changes predictably with temperature.
13. Which phenomenon causes a rainbow to display different colours after sunlight passes through raindrops?
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Correct Answer: A. Dispersion
Water droplets can disperse sunlight into its component colours because different wavelengths of light are refracted by different amounts.
Water droplets can disperse sunlight into its component colours because different wavelengths of light are refracted by different amounts.
14. Which type of heat transfer occurs mainly through direct contact between particles?
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Correct Answer: C. Conduction
Conduction transfers thermal energy through direct contact and interactions between neighbouring particles.
Conduction transfers thermal energy through direct contact and interactions between neighbouring particles.
15. Which layer of the Earth is composed mainly of liquid iron and nickel?
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Correct Answer: C. Outer core
Earth's outer core is a hot, liquid layer composed mainly of iron and nickel. Its movement contributes to Earth's magnetic field.
Earth's outer core is a hot, liquid layer composed mainly of iron and nickel. Its movement contributes to Earth's magnetic field.
16. What is molten rock called after it reaches Earth's surface?
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Correct Answer: B. Lava
Molten rock beneath Earth's surface is called magma. When it erupts onto the surface, it is called lava.
Molten rock beneath Earth's surface is called magma. When it erupts onto the surface, it is called lava.
17. Which celestial object produces its own visible light?
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Correct Answer: C. Star
Stars generate and emit their own light and energy through processes occurring within their interiors.
Stars generate and emit their own light and energy through processes occurring within their interiors.
18. Which planet is famous for its prominent system of rings?
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Correct Answer: C. Saturn
Saturn has a spectacular ring system made mainly of countless particles of ice and rock.
Saturn has a spectacular ring system made mainly of countless particles of ice and rock.
19. Which plant tissue transports water and minerals upward from the roots?
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Correct Answer: B. Xylem
Xylem tissue conducts water and dissolved minerals from the roots toward the stems and leaves.
Xylem tissue conducts water and dissolved minerals from the roots toward the stems and leaves.
20. Which process returns carbon dioxide to the atmosphere when living organisms break down food for energy?
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Correct Answer: A. Cellular respiration
During cellular respiration, cells break down energy-rich molecules and release carbon dioxide as a waste product.
During cellular respiration, cells break down energy-rich molecules and release carbon dioxide as a waste product.
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