Suppose that you close a window because you notice that rain is falling. Your action in closing the window is a(n) A. involuntary reaction.
B. depressant.
C. stimulus.
D. response.

Organisms are classified, or grouped into categories, based on similarities in their characteristics and/or evolutionary relationships. the study of how organisms are classified is known as

Which of the following is the source of energy for photosynthesis? a.) glucose b.) chlorophyll c.) carbon dioxide d.) sunlight

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