Fact 1: Energy is passed up a food chain or web from lower to higher trophic levels.

Fact 2: Calories are units of energy.

Given the two facts above, answer the question "what are passed up a food chain or web from lower to higher trophic levels?" with the following options: 
- calories
 - Light
 - atmosphere
 - DNA
 - heat
 - fossil fuels
 - animals
 - photons


 

 calories        