Which best describes the movement of energy and matter through living systems?
A. Energy flows while the matter is cycled.
B. Matter flows in two directions while energy flows in one direction.
C. Energy is cycled while some matter is lost as heat.
D. Energy forms chemical compounds while matter flows.
E. The matter is always available while energy is cycled.

Hint: The food chain shows how energy flows from one organism to another. In general, the energy flows from the sun to producers and then to the consumers. They get energy by eating grass and the leaves. Energy may be lost in the living systems as it flows through them.

Complete step by step answer: Energy is passed from one of the trophic levels to the next trophic level. Hence, energy flows through successive trophic levels in the food chain. The matter may be an organic or an inorganic. The organic and inorganic matter is produced, exchanged and moved within an ecosystem and this is called cycling. Hence, the matter is cycled. Energy and matter characterize in both physical and biological systems. These systems are defined by the types of energy and matter they contain and by how that matter and the energy move through between systems. In the natural system, both energy and the matter are conserved within a system. It means that the energy and the matter can change forms but cannot be created or destroyed. Energy and matter are often cycled within a system, and different forms of the matter and energy are able to interact. The surrounding environment must be considered while studying a system’s energy, and the matter to examine flow into and out of the system.
Scientists seek to study the flow and the interactions of matter and the energy, while engineers often seek to minimize inputs and to maximize outputs of matter and the energy relative to the given system.
Hence, the correct answer is option A.

Note: According to a framework, the crosscutting concept of energy and the matter can be used to develop understanding across physical, life, and Earth science disciplines. Due to the abstract and complex nature of the energy, the NGSS do not introduce energy concepts until grade three.