HS-LS2-5

If We Are What We Eat, Americans Are Corn and Soy

Description:  This CNN story and journal article show how big a role corn plays in the diet of typical Americans. Scientists can do isotope analysis of the carbon to determine the source of carbon. Corn production is heavily subsidized in the US and relies on large amounts of fertilizers and water.

Web Resources:  If we are what we eat, Americans are corn and soy - CNN, Carbon and nitrogen stable isotopes in fast food: Signatures of corn and confinement - PNAS

Public Domain, Link

Reconstructing Ancient Diets with Isotopes

Description:  Scientists are able to reconstruct the diet of ancient humans by analyzing the isotopes found in their bones and hair. For example by examining the 12C/13C isotope ratio they can determine if the diet was mainly wheat (a C3 plant) or corn (a C4 plant). They can also place the diet in different trophic levels based on the isotopes of carbon as well as nitrogen and oxygen. This phenomenon could start with the following question: Was the paleo diet truly the paleo diet?

Web Resource: Reconstructing Ancient Diets with Isotopes - Wikipedia

 
Paleo Diet.jpg

Vegetable Oil as Fuel

Description:  Vegetable oil can be used as fuel in both diesel cars and heating oil burners. Reclaimed vegetable oil that is used in food service industries could be used to reduce the amount of fossil fuels that are being used by humans. This phenomenon could be used in an energy unit related to either the physical or life sciences.

Web Resources:  Vegetable Oil Fuel - Wikipedia, Students Power Bus with Vegetable Oil - NBC

 

Biosphere 2

Description:  Biosphere 2 was created in the 1990's to model all the elements of Biosphere 1 (The Earth). Plants in the biosphere produced oxygen and food for the inhabitants. The carbon dioxide released during respiration was taken in by the plants cycling the matter with energy from the Sun. In this experiment oxygen levels steadily fell to dangerous levels and oxygen eventually had to be added to the biosphere. This large-scale phenomenon continues to be owned and run by the University of Arizona. The mystery of missing oxygen could be used as a phenomenon in a unit on matter cycling and energy flow. Students can even create biospheres of their own and monitor life over time.

Web Resource:  Biosphere 2 - Wikipedia

 

Algae Fuel and Food

Description:  Algae food and fuel hope to reduce human dependence on fossil fuels and avert food shortages around the world. Algae fuel works in the same way as fossil fuels but the carbon dioxide released during combustion is carbon taken from the atmosphere in algae photosynthesis. Algae can also be used to create animal feed which currently uses large amounts of soil and water resources. This phenomenon can be use in an energy unit or life science unit related to mass and energy.

Web Resource: Algae Fuel - Wikipedia

 

Air Plants - No Soil Needed

Description:  Air plants (Aerophytes) don't require soil to grow so they can use used as an introductory phenomenon as your students explore plant needs. Air plants live in areas with high humidity and are generally epiphytes (plants that live on but are not parasites of) living on larger trees. Air plants obtain the water they need to survive from the environment so they must either be misted or occasionally dipped in water.

Web Resource: Air Plant Care - HGTV, Air Plant Supply Co.