Answer:
The growth of the plants is the dependent variable, the stuff added to each plant is the independent variable, the plants that don't receive treatment/other stuff are control variables.
The adaptations that a coconut crabs also known as a robber crab is they use a special organ called branchiostegal lung that they use to breathe which other crabs have. This organ is a developmental stage between gills and lungs and is one of the most significant adaptations of the a coconut crab.
The amount of energy available as one moves up the energy pyramid decreases substantially.
Explanation:
At each trophic level, energy is lost primarily through heat loss and respiration.
In the image below, 100% of the energy from the plant is not available to the deer. As we move further from the primary producer (in the image below, the green plant), less and less energy is transferred.