They come from the atmosphere, since plants use carbon dioxide to produce carbohydrates :)
<span>The tone, before conditioned to salivation, is simply a stimuli that the dog is responding to or ignoring in it's environment. Since it has no taught reactions to this sound, it is simply part of the environment the dog is in.</span>
Prokaryotes: do not have a nucleus, use starch for energy, smaller ribosomes (70s)
eukaryotes: do have a nucleus, use glucose for energy, and have bigger ribosomes (80s)
Scientists<span> are people who use research and experiments to learn more about the natural world. </span>Scientists<span> use scientific methods to derive knowledge systematically, performing repeatable experiments to ensure that their conclusions are valid and accurate.</span>
<span>Helium nuclei have a positive charge of 2+ when observed. Compared to a hydrogen nuclei, we can see that the Helium nuclei is more difficult to fuse as it has a greater charge than Hydrogen 1+. This chemical difference makes the answer true.</span>
