Which best describes biogeographic isolation?

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Sydney drew a flow chart to illustrate the nitrogen cycle.which labels best complete the flow chart? x: producers undergo photosynthesis.y: nitrogen compounds are released into the air.x: nitrogen compounds are released into the air.y: producers undergo photosynthesis.x: free nitrogen is in the atmosphere.y: producers absorb nitrogen compounds through their roots.x: producers absorb nitrogen compounds through their roots.y: free nitrogen is in the atmosphere.

What does all of the organ system in a human form