If a pin is 0.001 m wide, how many red blood cells could you line up across a pin?

In which of the following relationships is one organism always benefited while the other organism is always harmed

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.

What do you need to use in order to work as an environmental scientist? you need to use the scientific method and__ in order to work as an environmental scientist.