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.
The total amount of matter and energy increased.
B.
Matter and energy were lost each time they changed locations.
C.
Matter and energy were lost each time they changed forms.
D.
The total amount of matter and energy remained the same.

Answer 1

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

Explanation: This follows the laws of conservation of mass and energy — matter and energy are neither created nor destroyed, only changed in form or location. Energy from the Sun was converted into chemical energy in the plant and later into other forms (movement, heat, waste), and matter was transformed and recycled by decomposition. (While usable energy decreases due to losses as heat and entropy increases, the total energy and total matter are conserved.)