Answer:
due to formation of purines in outer body
An observation is something you saw happen whereas an inference is something you think will happen. You can guess that the water will fall through a static filled comb, but you observed the water moved away from the comb instead. (I saw this happen and I thought it was so cool)
There are so many examples for that in different areas, like Perylene experiment carried out in our lab recently.Here's one link: http://www.alfa-chemistry.com/perylene-cas-198-55-0-item-282870.htm
Answer:
A carbon dioxide and water
All of the above points are valid for fossils' contributions in understanding the process of evolution. They allow us to study the ancestry, we can see the homologous organs or structures, if fossils are well-preserved; different fossils can lead us to follow the cycles of the changes that occurred during macroevolutions, and fossils can be used to study different populations which had different body structures for surviving in different environmental conditions.