1. What is the gradual change in populations over time? 2. What is the idea that species originate in small gradual steps over time?

This class has taught you that the use of science and medicine in practical ways has become an international endeavor. one of the greatest examples of an international science accomplishment is which allows the profiling of human dna, useful not only to science but also medicine. a) forensic science b) the fbi c) the human genome project d) bioterrorism

How many chromosomes does each human cell contain? a. 23 chromosomes b. 26 chromosomes c. 43 chromosomes d. 46 chromosomes

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?