In the graph, “ppm” stands for parts per million. A concentration of one ppm is a ratio of one part to one million parts. Concentrations can also be expressed as a percentage. Why do you believe scientists choose ppm over percentage in some cases?

92 sathe best for the question 11. most animals and plants reproduce sexually. this means that dna is passed down to new organisms from two parental organisms. which of the following is a key advantage of sexual reproduction?

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

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