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Energy. Emily Cordon IB Biology SL. http://www.248am.com. Light. Light is the most important energy source for almost every living thing.
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Energy Emily Cordon IB Biology SL http://www.248am.com
Light • Light is the most important energy source for almost every living thing. • Plants absorb light through a process called photosynthesis; carbon dioxide from air and water mix with light to form sugars. Light goes through the chloroplast of the cell and is converted to ATP.
Trophic Levels of the Food Chain • Producers – feed only off raw materials, like water and sunlight (e.g. plants) • Herbivores – a.k.a. primary consumers, feed off of vegetation (e.g. sheep) • Carnivores – a.k.a. secondary consumers, feed off of herbivores (e.g. snakes) • Carnivores – a.k.a. tertiary consumers, feed off of other carnivores (e.g. birds of prey)
Energy Flow in the Food Chain • Energy flow in food chains was analyzed by H.T. Odum. • Numbers in the flow chart are kilocalories per square meter per year (kcal/m2/yr). • Gross production – total calories acquired • Net production – calories left after respiration • Gross production is always higher than net production because the organism uses the energy to stay alive, and some is also lost due to decay. • The values decrease as trophic levels go up. • The ratio of the net production of a lower trophic level compared to the next trophic level is called conversion efficiency. • The energy transformations between the trophic levels in the flow chart are never 100% correct.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.htmlhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.html
The Pyramid of Energy • When the numbers of all the trophic levels are stacked up, they make the shape of a pyramid because the total amount of energy decreases as the trophic levels increase. • For example, the net production of energy in spiders will be less than the insects they fed off of, and the insects’ energy will be less than the plants they fed off of.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.htmlhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.html
Bird http://www.netstate.com Spider http://www.markleyspest.com Fly http://www.mypetjawa.mu.nu Grass http://www.inkycircus.com
Nutrients • Energy is used up by organisms, but nutrients from light and other factors need to be recycled for the food chain to continue. • For example, in the previous food chain, the grass was eaten by the fly, the fly was eaten by the spider, and the spider was eaten by the bird. If there was nothing to eat the birds, and the birds just simply died, the dead bird’s nutrients need to be returned to the producers. The producers, like grass, absorb the dead bird’s nutrients so the food chain can continue.
Decomposers • Saprotrophic bacteria and fungi, a.k.a. decomposers, recycle nutrients by taking up carbon and other minerals from dead animals or other waste. After they store the minerals, they release them out into the ground so other plants can take them up. http://www.diseaseproof.com
Bibliography • van derPluijim, Ben. "Introduction to Global Change."The Global Change Program. Geoscience Education, 2006. Web. 13 Aug 2010. <http://www.globalchange.umich.edu/>. • Food Chains . N.p., 23 April 2010. Web. 13 Aug 2010. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/. • "What do fungi do? ." FungiBank. N.p., n.d. Web. 13 Aug 2010. <http://www.fungibank.csiro.au/topic_3_2_1.htm>. • G. , Jayd. "Nutrients must be Recycled." Yahoo! Answers . Yahoo!, 2008. Web. 13 Aug 2010. <http://answers.yahoo.com/question/index?qid=20080913212336AAVyfMW>.
