Selected MCQ

Current Question
Which gas is used in respiration?
  • A. CO₂
  • B. O₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
Oxygen is required.
Related Question 1
Which gas is produced in respiration?
  • A. O₂
  • B. CO₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
Respiration releases CO₂.
Related Question 2
Which gas is used in photosynthesis?
  • A. O₂
  • B. CO₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
CO₂ is fixed into glucose.
Related Question 3
Ocean acidification is mainly caused by increased dissolution of atmospheric:
  • A. Nitrogen
  • B. Oxygen
  • C. Carbon dioxide
  • D. Methane only
Correct Answer: C
Explanation:
Dissolved (CO_2) forms carbonic acid, lowering seawater pH.
Related Question 4
Which scale is logarithmic and used to describe earthquake magnitude?
  • A. Beaufort scale
  • B. Mohs scale
  • C. Richter-type magnitude scale
  • D. Saffir-Simpson scale
Correct Answer: C
Explanation:
Earthquake magnitude scales quantify released energy logarithmically.