Study the definition.

consists of different organs that work together to carry out major body functions

Which correctly matches the definition?

lungs

respiratory system

blood vessels

blood cells

Has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure

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.

When a population split into two subgroups what is most likely to cause the subgroups to develop different traits?