1. Which of the following is NOT considered a benefit of microorganisms? a. nitrogen fixation c. synthesis of vitamins b. production of fermented foods d. causative agents of disease ANS: D DIF: Easy REF: 1.1 OBJ: 1.1a Describe how we define a microbe, and explain why the definition is a challenge. MSC: Remembering 2. A microbe that is 50 nm in size would most likely be a. fungi. c. virus. b. E. coli. d. algae. ANS: C DIF: Moderate REF: 1.1 OBJ: 1.1b Describe the three major domains of life: Archaea, Bacteria, and Eukarya. Explain what the three domains have in common and how they differ. MSC: Applying 3. Based on the figure shown, the type of organism indicated with an arrow could be a a. virus. c. macroscopic fungi. b. bacteria. d. large ameba. ANS: B DIF: Easy REF: 1.1 OBJ: 1.1b Describe the three major domains of life: Archaea, Bacteria, and Eukarya. Explain what