As the water in the hollow evaporates the minerals are concentrated and eventually form layers and occasionally crystals. Describe the difference. A food chain is a direct link from one organism to another. A food web involves many links between organisms. Both the food chain and the food web enable energy to be passed from one living thing to another.
Coyotes are naturally shy of man and help to keep small animal and rodent populations under control.
Scientists do not know for sure what color dinosaurs' skins were, but they can make educated guesses based on modern day reptile specimens. Imprints of fossilized dinosaur skin have been found and seem to have a scaly texture similar to modern reptiles. Scientists study fossils to learn about the history of our planet including its lifeforms. Petrified wood can help us to determine climactic conditions in distant eras of time. Due to the hand cutting of dies, and the hand striking of the blanks of silver, no two coins were exactly the same.