A scientist removed the cell membranes from bacteria cells in a culture. She analyzed the cell membranes for specific molecules. Which of these was probably the most common type of molecule present in the bacterial cell membranes?

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d

Which of the following is a true statement? a. individuals evolve to have adaptations. b. individuals have adaptations that can change over time. c. individuals have traits that may or may not make them successful at reproduction. d. populations cant evolve, only individual organisms.

Which of the following determines the specificity of a dna probe? a. type of radiation b. level of enzymatic activity c. number of neutrons d. complementary base pairing