food webs + trophic levels

Food chains

-food chains show simplest path of energy between organisms

• energy goes from producer to consumers
• arrows point to where energy goes
• decomposers normally left out

Food web

-made of many food chains

Trophic pyramid

• bottom to top: producers, primary consumers, secondary consumers, tertiary consumers
• energy goes from sun to producers, then up trophic levels
• higher up pyramid = less energy available, populations smaller

Trophic levels

• how organisms get energy
• higher level = farther away from original energy source

Autotrophs

producers

Heterotrophs

consumers

Rule of 10%

• around 10% of energy from one level passed up
• energy lost as heat, daily activities, inedible parts, etc.