A substance with a pH of 6 is called O a base. O neither an acid nor a base. O an acid. O both an acid and a base.

Which of the following statements about archaea and bacteria is true? a. neither is single-celled. b. they both have nuclear membranes. c. neither reproduces by binary fission. d. they both lack a nuclear membrane.

Which of the following is a true statement? question 8 options: populations can't evolve, only individual organisms. individuals have adaptations that can change over time. individuals have traits that may or may not make them successful at reproduction. individuals evolve to have adaptations.

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population. b) the separated population is small, and genetic drift occurs. c) the isolated population is exposed to different selection pressures than the ancestral population. d) different mutations begin to distinguish the gene pools of the separated populations. e) gene flow between the two populations is extensive.