Food Chains and Food Webs
The majority of energy used for life on Earth comes from the sun. Energy from the sun is converted into many different forms.
The majority of energy used for life on Earth comes from the sun. Energy from the sun is converted into many different forms.
- Sun is responsible for photosynthesis (chemical process that makes glucose out of carbon dioxide and water)
- Glucose is responsible for the growth and well being of plants
- Plants are producers, which makes them an essential part of the food chain, because they feed an entire population of animals called herbivores, who are sometimes eaten by other animals known as carnivores (meat eaters), or omnivores (plant and meat eaters).
- This hierarchy of a food chain is called trophic levels (trophic means "feeding")
- Each time energy is transferred to a different trophic level energy is lost (only about 10% of the energy from the previous level is transferred)
- "For every 100 calories of solar energy captured by producers, 10 calories are transferred to herbivores and 1 calorie is transferred to carnivores."--Text Book
- Scientist organize this transfer of energy (especially the loss of energy) on a diagram called a ecological pyramid.
- The health issues involving ecological pyramids are
- Many humans rely on meat, when we could feed more people with a vegetarian diet
- At the higher trophic levels there are more non-degratable "left overs."
- Another health risk includes animals eating other animals that have been exposed to toxic chemicals or disease.
Stop and Think....
1. Is it possible to have a world of Vegetarian Humans, what positive and negative effects would this have?
3. (From book) The traditional diet of the lnuit, one of the native people of North America coast, is part of a relatively long food chain:
Diatoms (producers)-----> Tiny marine animals ---->
Fish----> Seals---> lnuits
How might the length of this food chain be one factor contributing to the small population size of lnuits groups?
1. Is it possible to have a world of Vegetarian Humans, what positive and negative effects would this have?
3. (From book) The traditional diet of the lnuit, one of the native people of North America coast, is part of a relatively long food chain:
Diatoms (producers)-----> Tiny marine animals ---->
Fish----> Seals---> lnuits
How might the length of this food chain be one factor contributing to the small population size of lnuits groups?