Sunlight as principal energy source explains how energy flow, matter cycling or carbon transfer is represented, measured or limited within ecosystems.
Sunlight supplies most ecosystem energy.
Photosynthetic producers capture photons and convert part of that energy into chemical energy in organic molecules. The captured energy supports consumers only after it enters biomass.
light → photosynthesis → chemical energy → producer biomass → consumers.
A leaf converts absorbed light into carbohydrates that later supply energy to a herbivore through feeding.
Sunlight is the principal input for most ecosystems, not a source of matter such as carbon atoms.
This objective is assessed through structured response, commonly using State / Explain.
State / Explain
Build the answer around this relationship: Sunlight as principal energy source must be linked to the correct source, store, transfer or loss process.
Skipping the conversion of light energy into chemical energy by producers.
Representative question
Explain how the energy supply in an ecosystem is dependent on sunlight.
a. plants/autotrophs use sunlight in photosynthesis;
b. light energy is captured by chloroplasts/chlorophyll;
c. converting light energy to chemical energy;
d. this converts inorganic molecules into organic molecules;
e. plants (other photosynthetic organisms) are producers;
f. plants/producers are eaten by primary consumers/animals/heterotrophs;
g. energy transfers through a food chain/web/trophic levels;
h. at each stage of the food chain/web/trophic levels energy is lost (as heat/respiration);
i. about 10 % of the energy reaches the next trophic level;
j. energy flow being linear/one-direction/not cyclic;
d. Accept word equation or chemical equation for photosynthesis.
f. Can be shown in a labelled drawing.
7 max