Organisms at each level of the food web use the energy for and some of the energy is released as heat energy.

I don't know the exact word they want, but organisms use energy for motion and any activity they perform regularly. (eg: hunting, climbing, digging, etc.)

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]