What does it mean to say that enzymes are specific?

Based on the topographic map of mt. st. helens, what is the contour interval of the volcano about height is 2,950 m?

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.

Which of the following is not a benefit of genetically modified foods? a.pest-resistant crops b.herbicide-resistant crops c.plants that do not require water?