As energy moves through trophic levels in an ecosystem the amount that is available decreases. ... A: Energy flows in a food web by being transferred to and between organisms as they undergo photosynthesis, are consumed by another organism, or decompose.
Answer:
They are called covalent bonds.
Explanation:
I just went through the lesson.
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.