Approximately what percent of the energy is transferred from one trophic level to the next?

Which element provides strength to the exoskeleton of clams and oysters

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.

What might explain the real-world results, show in the graph to the right, for one class of twenty students? check all that apply.