Question

A highly diverse ecosystem churns out oxygen, organic macromolecules like glucose and a healthy amount of decaying matter with high efficiency. Which ecosystem product contributes directly to ecosystem productivity?

• A. Oxygen
• B. Glucose
• C. Decaying matter
• D. Carbon dioxide

Answer 1

The correct option is B Glucose

Since productivity is a measure of biomass per unit area, in order to gain biomass, plants need to expend energy and use the energy to generate new plant material including new cells and tissues. Via the process of photosynthesis, plants generate glucose which is stored and used later for many processes including growth and reproduction. Hence, the generation of glucose directly contributes to the generation of new plant tissue and thereby, to the generation of biomass. The measure of biomass in a given area is productivity. Although oxygen might seem like a good measure of productivity, it is released as an unintended consequence of photosynthesis. Therefore, oxygen doesn’t directly contribute to ecosystem productivity.