- An example of energy flow (kJ m⁻² year⁻¹) in the North Sea is shown.
(a) Identify the trophic level represented by C. [1]
(b) Sketch a pyramid of energy for the trophic levels represented by A, B, C and D. [2]
(c) State two sources of energy for X. [1]
(d) Explain the reasons that little energy is transferred between trophic levels, apart from that transferred to X. [2]