Which is more important systolic or diastolic blood pressure? why?

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

You see a white marker with an orange circle and black lettering. what does this marker tell you

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.