Natural Science MCQs

Questions and Answers (1–30)

1. What is the basic unit of life?

Answer: Cell

2. Which gas is essential for respiration?

Answer: Oxygen

3. Which planet is known as the Red Planet?

Answer: Mars

4. What is the chemical formula of water?

Answer: H₂O

5. Who discovered gravity?

Answer: Isaac Newton

6. Which part of the plant performs photosynthesis?

Answer: Leaves

7. What is the SI unit of force?

Answer: Newton

8. Which metal is liquid at room temperature?

Answer: Mercury

9. What is the largest planet in the solar system?

Answer: Jupiter

10. Which organ pumps blood in the human body?

Answer: Heart

11. What is the boiling point of water?

Answer: 100°C

12. Which vitamin is produced in the human body by sunlight?

Answer: Vitamin D

13. What is the SI unit of energy?

Answer: Joule

14. Which gas do plants absorb during photosynthesis?

Answer: Carbon dioxide

15. Which planet is closest to the Sun?

Answer: Mercury

16. What is the hardest natural substance?

Answer: Diamond

17. What is the main component of air?

Answer: Nitrogen

18. What is the center of an atom called?

Answer: Nucleus

19. Which organ is responsible for breathing?

Answer: Lungs

20. What is the SI unit of temperature?

Answer: Kelvin

21. Which planet is known for its rings?

Answer: Saturn

22. What type of energy is stored in food?

Answer: Chemical energy

23. What is the speed of light?

Answer: 3 × 10⁸ m/s

24. What is the process by which plants make food?

Answer: Photosynthesis

25. Which blood cells fight infections?

Answer: White blood cells

26. What is the SI unit of power?

Answer: Watt

27. What is the largest organ in the human body?

Answer: Skin

28. Which part of the Earth is molten?

Answer: Core

29. What is the nearest star to Earth?

Answer: Sun

30. What is the process of converting liquid into vapor called?

Answer: Evaporation