Biology 9700 · AS & A Level · Movement into and out of cells

Movement into and out of cells — practice question

What is the smallest number of cell membranes that a molecule of carbon dioxide and a molecule of oxygen cross during gas exchange between alveoli and the plasma in the capillaries?

  • Acarbon dioxide: 2, oxygen: 4
  • Bcarbon dioxide: 3, oxygen: 5
  • Ccarbon dioxide: 4, oxygen: 4
  • Dcarbon dioxide: 4, oxygen: 5

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI