If a mechanic analyzes a car engine as a system, which of the following represents the primary 'energy' component that drives the system?

The pistons that move up and down.

The chemical energy stored in gasoline.

The metal frame of the engine block.

The exhaust gases released from the tailpipe.

When modeling the process of photosynthesis in a plant leaf as a system, what is the primary 'energy' input?

The chlorophyll that captures light.

The carbon dioxide taken from the air.

The glucose sugar that is produced.

To prove that the event is too complicated for a single theory to explain.

To understand how the individual parts interact to make the whole system function.

To list every single object involved in the event, regardless of its importance.

To focus only on the energy source and ignore the matter and structures.

The heat from the sun warming the pond.

The algae producing food through photosynthesis.

The rocks and mud that form the bottom of the pond.

The dissolved oxygen that fish breathe.