Controlled burning? I think that's right.
The correct answer is chloroplast. If an organism has chloroplasts then it will be an autotroph because it will be able to make its own food by the means of photosynthesis. This is common for plants but there are some bacteria that can photosynthesize as well. If you don't have them you have to feed on other organisms that have energy for you.
Activation energy - is the minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.
