An ecosystem is all the populations of organisms that live together and
a. the microorganisms that depend on them.
b. the organisms that generate energy from sunlight.
c. the physical factors with which they interact.
d. the food that they take in as energy.

Plants use light energy to make sugars from carbon dioxide ... They make their own food thru the processof photosynthesis using light energy to ... In photosynthesis carbon dioxide from the air and water from the soil react with the sun's energy to ... tiny subcellular structures contained in the cells of leaves andgreen stems.

The horse latitudes-high-pressure zones about 30 degrees north and 30 degrees south of the equator.-warm air traveling away from the equator cools and sinks-weather tends to be clear and drythe doldrums-low-pressure near equator-air rises and spreads out toward the poles-rising moist air produces clouds and heavy rainthe westerlies-blow from the west-move from the horse latitudes toward the poles.-bring storms across much of the united statesthe tradewinds-blow from the east-move from the horse latitudes toward the equator  -strong, steady winds