Question

3.3.2 quiz: investigate cycling of o₂ and co₂
diagram: sun, chloroplast, mitochondrion, arrows: co₂ + h₂o into chloroplast, o₂ out, sugar out; sugar into mitochondrion, atp out, heat out, co₂ + h₂o out
options:
a. o₂-co₂ cycle
b. denitrification
c. transpiration
d. slow carbon cycle

Explanation:

The diagram shows chloroplast (photosynthesis: uses \(CO_2 + H_2O\), produces \(O_2\) and sugar) and mitochondrion (respiration: uses sugar and \(O_2\), produces \(CO_2 + H_2O\), ATP, heat). This represents the cycle of \(O_2\) and \(CO_2\) between photosynthesis and respiration. Denitrification is about nitrogen, transpiration is water loss in plants, and slow carbon cycle involves geological processes. So the correct option is A.

Answer:

A. \(O_2 - CO_2\) cycle