E)none of the above because guanine doesn't change, only thymine into uracil.
Carbon Dioxide (or CO2) is produced by the lungs I think because when you inhale, you breathe in oxygen, then you exhale the carbon dioxide in the lungs. That's actually 3 and 4. As for number 2, I want to say either the alvioli or however that's spelled but technically, the entire body uses oxygen so I'm not sure.
Answer: Euglena is a large genus of unicellular protists: they have both plant and animal characteristics. All live in water, and move by means of a flagellum. This is an animal characteristic. Most have chloroplasts, which are characteristic of algae and plants.
Answer:
Mercury, Earth, Mars, Saturn, Jupiter, Uranus, Venus, Neptune
*These are not listed above in any order do not confuse.