Energy is passed up a food chain or web from lower to higher trophic levels.
Calories are units of energy.
Calories are passed up a food chain or web from lower to higher trophic levels.
what are passed up a food chain or web from lower to higher trophic levels?
Options:
  - calories
  - Light
  - atmosphere
  - DNA
  - heat
  - fossil fuels
  - animals
  - photons