TROPHIC LEVELS AND 10% RULE

In-ground Pool For Crying out Loud

Sit Ups

TROPHIC LEVELS AND 10% RULE

Each level in a food chain or web is called a trophic (feeding) level.

Trophic Levels:

Primary Consumer: Herbivores or omnivores that consume the producers.

Secondary Consumer: Omnivores and carnivores that consume primary consumers.

Target: I will be able to identify the organisms who occupy each trophic level in a food web, and compare organisms in different trophic using the 10% rule.

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Tertiary Consumer: Omnivores and carnivores that consume secondary consumers.

Quaternary Consumer: Omnivores and carnivores that consume tertiary consumers.

Producer

Primary consumer

Secondary consumer

Tertiary consumer

Producer

Primary consumer

Secondary consumer

Tertiary consumer

Quaternary consumer

Label the Producers, Primary, Secondary, Tertiary, and Quaternary Consumers.

10% Rule: Only about 10% of the energy available at one trophic level is transferred to organisms at the next trophic level.

The rest of the energy is used for life processes or lost to the environment as heat energy or waste at each level.

Pyramid of Energy: Shows that the energy available to organisms decreases with each trophic level.

Pyramid of Biomass: Shows that the total amount of biomass (total living tissue in all members of a population) decreases with each trophic level.

Pyramid of Numbers: Shows that the relative numbers of organisms decreases with each trophic level.

Summary:

UNDERSTANDING ENERGY PYRAMIDS

1. Draw a Pyramid of Energy with 5 sections and label the trophic levels. (Producer, Primary Consumer…Quaternary Consumer)

2. Draw organisms in each level (as you would to show what eats what in that food chain).

3. Label the amount of energy being transferred on the side of each section.

4. Explain (at least 2 sentences) why only 10% is available to be passed onto the next trophic level using the 10% rule.

*Use a minimum of 4 colors and good grammar.

*Paste trophic level worksheets over the top so you can see your drawing below. Pg. 34