What do the arrows in a food chain represent?

Related questions

• What would be an example of a food chain in the rainforest?
• What would be an example of a food chain in the desert?
• How is a food chain related to energy flow within an ecosystem?
• How do producers and consumers relate to trophic levels?
• What secondary consumers live in the tundra?
• How does matter differ from energy in a food chain?
• Why are most communities best represented with a food web instead of a food chain?
• What is the concentration of pollutants within the food chain?
• What level consumer is an organism that eats only plants?
• What is bioaccumulation and how does it affect species in a food chain?