Which of the following sentence best describes a buffer?
buffers resist change in ph of solutions by neutralizing excess acid or base.
buffers change the ph of solutions by increasing acidity or basicity of solutions.
buffers change the ph of solutions by decreasing acidity or basicity of solutions.

List charasteristics of athenosphere

Select the situation bellow that would produce a total displacement of zero. a. a trip to the moon and then to mars b. a horse galloping from one end of a field to another c. the criss-crossing path of a bug as it flies from flower to flower d.a round-trip ride to school and back

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.