Question

Through the process of photosynthesis, light energy from the Sun was transformed into chemical energy in the form of sugar within a strawberry plant. The strawberries were then eaten by a bird, and the sugars were converted into other essential molecules, such as proteins or fats. When the bird produced waste, bacteria in the soil decomposed the waste into elements, such as carbon and nitrogen, which were recycled back into the ecosystem.

In this example, matter and energy changed forms and locations as they flowed through the ecosystem. What else is true?
A.
Matter and energy were lost each time they changed forms.
B.
The total amount of matter and energy remained the same.
C.
Matter and energy were lost each time they changed locations.
D.
The total amount of matter and energy increased.

Answer 1

B. The total amount of matter and energy remained the same.

Explanation: Matter is conserved (atoms are recycled through photosynthesis, consumption, and decomposition). Energy is conserved too — it changes forms (light → chemical → kinetic/heat) and is transferred, but not created or destroyed. (Note: energy can be dispersed as heat to the surroundings, so less usable energy may be available for work, but the total energy is conserved.)