3. C6H12O6
4. Organic compounds are compounds made up of carbon that are typically linked to hydrogen (H), oxygen (O) and/or nitrogen (N). Glucose has C, H and O which makes it (and any other carbohydrate) organic.
5. Sugar (glucose) is in a lot of foods - bread, rice, pasta, potatoes....
6. On the label it will have the number of calories in the food (per serving!) - this is how much energy there is in that amount of the product.
As the world evolves, there is a change in the ecosystem, and with that comes the fluctuation. Organisms have have changing populations as they adapt, slowly die out, or thrive in the new ecosystem.
Probaly abiotic would be the most likely answer in my opinion.
The 1st Law of Thermodynamics is what you are looking for
Hope this helped :)