1, as the energy comes from the sun, then plants get it through photosynthesis, and finally the consumers obtain the energy from consuming animals on a lower trophic level than themselves. energy cannot flow down the food chain, only up.
PH – depends on the environment the cell that is respiring is in.
Temperature; as it increases, the rate increases…to a point (too hot and enzymes denature!)
Length times Width times Height
Hope i help!