The younger layers of rock in the Grand Canyon are on top of the older layers. Which of Steno’s principles best explains this?

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

Glycogen is an energy-storage molecule in humans. a hormone that is called insulin controls the storage of glycogen in the liver. insulin is made up of amino acids.

What are the fixed alleles in the human species? o a. the alleles that are on the most chromosomes b. the alleles that change most often 000 c. the alleles that no one has d. the alleles that everyone has