The diver in this photo is a living system. The scuba, or self-contained underwater breathing apparatus, gear is a system of air exchange. How are these two systems interacting?

Which of the following is the best definition for the process of photosynthesis? a.) plants digest sugars to make energy. b.) plants use oxygen and glucose to make carbon dioxide. c.) plants use sunlight and carbon dioxide to make sugars. d.) plants use sunlight to make chlorophyll and chloroplasts.

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome