Aclient who has syphilis tells the nurse that it must have been contracted from a toilet seat. the nurse knows that this cannot be true because of what property of the causative agent of syphilis?

Which codon is the code for the amino acid histidine (his)?

Which of the following is a period in the paleozoic era? devonian cambrian permian all 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.