Which of these actions does NOT result in a physical change?
leaving an ice cube in a glass at room temperature
folding a piece of paper into a paper airplane
burning a log in a fireplace
mixing sugar into a pitcher of iced tea

What is a group of organisms that are closely related and share similar characteristics

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations