Free account: track your progress — Sign up free

GCE Biology 2025 Objective — Question 9

Question 9 of 50 from the General Certificate of Education (GCE) Biology 2025 Objective paper, with the correct answer and a full explanation.

Advertisement

How many molecules of oxygen are required for the aerobic respiration of three molecules of glucose?

  • A. 3
  • B. 6
  • C. 12
  • D. 18Correct

Explanation

The general equation for aerobic respiration is C6H12O6 + 6O2 -> 6CO2 + 6H2O. From the equation, 1 molecule of glucose takes 6 molecules of oxygen. Thus, for 3 molecules of glucose, the required number of oxygen molecules = 3 x 6 = 18.

Advertisement

Sign up free to unlock

  • Score tracking
  • Practice history
  • Saved questions
  • Progress dashboard
  • Personalized sessions
  • Weak-topic breakdown

…and/or go further with premium services and No Ads.