Scientists use fossils to learn about

how future organisms will interact
how living things change over time
the personalities of extinct animals
the amount of protein in an extinct animal's diet

What enzyme is most important for dna replication and why?

What happens when two nitrogen atoms share electrons

Many body systems work together for proper functioning of the body and to maintain internal homeostasis. the works to break down food eaten before exercising. the takes in the nutrients obtained from the food. the body sweats as a mechanism to cool off, because the is working to flush out toxins.