As you point out, plants break down the water molecules to produce the oxygen, but the CO2 is the fuel used for that process, just as my engine produces torque by using a combination of fuel (gasoline or diesel) and air.
You can choose a DNA without a subscription to the Ancestry.com service, a DNA test with a subscription to U.S. discovery service or a DNA test with World explorer. Once you choose an option, Ancestry.com will ship you a test kit. The test kit has a small mouth swab which you wipe on the inside of your mouth.
Scientists study DNA for many reasons: They can figure out how the instructions stored in DNA help your body to function properly. They can use DNA to make new medicines or genetically modify crops to be resistant to insects. They can solve who is a suspect of a crime, and can even use ancient DNA to reconstruct evolutionary histories! To get the DNA from a cell, scientists typically rely on one of many DNA extraction kits available from biotechnology companies. During a DNA extraction, a detergent will cause the cell to pop open, or lyse, so that the DNA is released into solution. Then alcohol added to the solution causes the DNA to precipitate out. In this activity, strawberries will be used because each strawberry cell has eight copies of the genome, giving them a lot of DNA per cell.