The nurse is educating a client with hyperthyroidism who has recovered from thyrotoxicosis (thyroid storm) and is preparing for discharge. what can the nurse inform the client that this hypermetabolic state can be caused by in order to decrease exacerbation? select all that apply.

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.