Photosynthesis

2. Animals benefit indirectly from photosynthesis because they, too, must have sources of ______.
5. ________energy from the Sun is changed to chemical energy in the form of glucose molecules.
6. Earth’s atmosphere has not always contained ______________ gas.
7. Scientists are doing a lot of __________ to find ways to bring costs down so that the process of making biofuels becomes economical
11. Joseph Priestley was one of the first ____________ to observe a product of photosynthesis.
13. When algae grows so fast that it harms other organisms it is called an algal _______.
15. If photosynthesis can produce the kind of fuel that our bodies use, it could also produce the kinds of fuels that_______use.
16. _______________is necessary for life on Earth

1. ___________ are tiny plankton that require light to live.
3. ____________________is one of the products of photosynthesis.
4. _________have been produced from corn, sugarcane, soybeans, and sunflowers.
8. When ___________________populations grow too quickly in a body of water, they can harm other organisms in the ecosystem.
9. Millions and millions of tiny creatures produced enough oxygen to change the composition of Earth’s______________.
10. Only three elements are present in the products of photosynthesis: _____________, hydrogen, and oxygen.
12. It takes six molecules of water and six molecules of carbon dioxide to make one molecule of __________.
14. __________________is a form of energy that most plants take in and use to carry out photosynthesis.