You analyze a dna sample which gives an a260 of 1.74 and a280 of 0.64. what is the concentration of this dna sample? is it sufficiently pure?

Organisms that successfully adapt will leave to grownone of the above

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.

This is an active transport mechanism by which cells pump sodium and potassium ions against the concentration gradient