Thursday, October 11, 2007

"Trophic Levels 1"

Bellwork:
1) Food is made by ________________.
2) Where is food used in the food web?
3) Organisms consume food because __________________.

- Review: Food webs and the flow of energy through them
- Vocabulary: added to glossary on page 33 (or 35)
Trophic Levels: the levels in a food chain or web through which energy flows; usually represented by a pyramid
- Trophic levels are the different levels in the food web (producer, primary consumers, secondary consumers, and so on)
- Question of the Day: Is all the food energy consumed by a brine shrimp passed on to the gull when it eats the brine shrimp?

- Read "Trophic Levels" in Populations and Ecosystems Resources book (pages 17-21)
- The 10% Rule: only 10% of the food you eat and energy you get becomes part of your body (your biomass) and becomes capable of being passed on. 90% of the food/energy you consume is used to survive and do work. So there are more producers than any other trophic level, and each trophic level decreases in biomass (amount of living stuff).

- Draw a food pyramid that includes organisms from a food chain on page 56 in the yellow workbook