What is the main function of the scrotum user: sperm deposited in the vagina are capable of fertilization for about how long?

This is one of the five kingdoms in the older biological succession. organisms in this kingdom are prokaryotic

To maintain asepsis when administering an injection, all parts of the syringe can be handled except the:

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.