45. Which of the following is NOT an example of a theory? A) Diseases are caused by germs. B) C) Molecules are composed of atoms. Organisms are composed of cells. Species evolve through natural selection. D) E) All of the above are considered to be theories. 46. To absorb large particles, cells engulf them within their plasma membrane in a process called: A) replication. B) transcription. C) endocytosis. D) translation. E) exocytosis. 47. Which of the following is usually employed before the others by an investigator using the scientific method? A) make observations B) C) D) E) conduct a critical experiment formulate a hypothesis devise a testable prediction analyze data 48. One important difference between covalent and ionic bonds is that: A) in covalent bonds two atoms share electrons while in ionic bonds two atoms of opposite charge are attracted to each other. ionic bonds only occur among water-soluble elements. in ionic bonds both protons and electrons can be shared while in covalent bonds only electrons can be shared. D) ionic bonds are much stronger than covalent bonds. E) in ionic bonds two atoms share electrons while in covalent bonds one atom gives one or more electrons to the other atom. B) C) 49. Which of the following is the most important factor governing a cell's particular type of interaction with other cells? A) The pattern of proteins on the cell's surface B) The location of the cell within an organism C) Whether or not the cell is an animal cell or a plant cell D) Whether or not the cell is eukaryotic or prokaryotic E) The type of animal the cell came from