Food Webs & Energy Transfers by: R.Morales

1. Food Webs & Energy Transfersby: R.Morales

2. Energy Flow • All living things are made of matter & need energy • Matter and energy move through the natural world • Matter is recycled over and over again, but energy is CONVERTED • This conversion is important to all life on Earth pg. 482 • Photosynthesis • Chemosynthesis • Hydrothermal Vents

3. Food Chains • Energy is transferred from one organism to another through eating producers or other consumers • Consumers: organism that obtains energy by eating other organisms • Producers: organism that makes its own food (plants) • Decomposers: organisms that obtain energy for life when the break down organic material • Identifying • Discussing the Connection and relationship among them* A food chain is a simple model to show how the energy (as food) passes from one organism to another - arrows indicate the direction of the energy flow - usually only 3-4 links - at each transfer energy is lost as thermal energy (1st link has more than last link) Acquatic plants -> insects -> bluegill -> bass -> humans

4. Visualizing the Food Chain Some Practice Let’s take a look at pg. 537

5. How do organisms “relate” to each other? • Predation- describes a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked) • Parasitism- A parasitic relationship is one in which one organism, the parasite, lives off of another organism, the host, harming it and possibly causing death. The parasite lives on or in the body of the host. • Commensalism- is a class of relationship between two organisms where one organism benefits but the other is neutral (there is no harm or benefit). • Mutualism- is a relationship in which both animals benefit

6. Recap • Commensalism - there is no harm or benefit • Mutualism- where both organisms benefit • Competition- where both organisms are harmed • Parasitism- one organism benefits and the other one is harmed. • Symbiosis

7. Food Webs • Food chains are very simple and don’t really give us an entire picture of how energy flows • A food web is a series of overlapping food chains • Provides a more complete model • Shows how organisms are part of many food chains Compare & Contrast: when compared to a food chain, a food web provides a more complete model of the feeding relationships in a community

8. Real Life:

9. Energy Pyramid • * The amount of energy is reduced as the energy travels through each link of a food chain (from animal to animal) • An Energy Pyramid shows the available energy at each feeding level

10. Energy Pyramid Explained • The bottom of the pyramid (producers) is the largest and first feeding level – it contains the most energy • As you move up the pyramid less energy is transferred and it is less efficient • Each level becomes smaller and smaller

11. Food Chain & Energy Web - RECAP • GIZMO: Food Chain LAB