AP BIOLOGY

Detailed explanation-1: -Gross primary productivity, or GPP, is the rate at which solar energy is captured in sugar molecules during photosynthesis (energy captured per unit area per unit time). Producers such as plants use some of this energy for metabolism/cellular respiration and some for growth (building tissues).

Detailed explanation-2: -Only a small fraction of energy reaches photosynthetic organisms. Of that, only 1 to 2 percent of the solar energy is converted to chemical energy.

Detailed explanation-3: -Plants typically transform light into chemical energy with a photosynthetic efficiency of 3–6 percent.-Unconverted absorbed light is dissipated mainly as heat, with a small fraction (1–2 percent) re-emitted as chlorophyll fluorescence at longer (redder) wavelengths.

Detailed explanation-4: -Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis, i.e., the rate at which light energy is converted into chemical energy.

Detailed explanation-5: -primary productivity, in ecology, the rate at which energy is converted to organic substances by photosynthetic producers (photoautotrophs), which obtain energy and nutrients by harnessing sunlight, and chemosynthetic producers (chemoautotrophs), which obtain chemical energy through oxidation.