BIOD 171 Microbiology Practice Exam (100 Questions)with Answers

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BIOD 171 Microbiology Practice Exam (100 Questions)

Section 1: Cellular Structure & Macromolecules (Questions 1–20)

1. What is the smallest biological unit of life?
A. Atom
B. Molecule
C. Cell
D. Organism
Answer: C

2. At a generalized level, all cells are comprised of what?
A. Proteins, lipids, nucleic acids, and polysaccharides
B. Amino acids, nucleotides, and fatty acids
C. Water, salts, and minerals
D. Carbohydrates, proteins, and vitamins
Answer: A

3. What is the plasma membrane composed of?
A. Proteins only
B. Lipids (hydrophobic hydrocarbons)
C. Carbohydrates and proteins
D. Nucleic acids
Answer: B

4. Which of the following are TRUE regarding the plasma membrane? (Select all that
apply)
A. Restricts movement of materials in and out of the cell
B. Is often a triple layer comprised of lipids
C. Prevents essential nutrients from escaping
D. Contains hydrophobic tails pointing outward
Answer: A and C

5. What is the primary difference between prokaryotic and eukaryotic cells?
A. Prokaryotic cells have a nucleus; eukaryotic cells do not
B. Eukaryotic cells contain a nucleus; prokaryotic cells do not
C. Prokaryotic cells are larger than eukaryotic cells
D. Eukaryotic cells lack a plasma membrane
Answer: B

6. Prokaryotic cells can be subdivided into which two domains?
A. Animalia and Plantae
B. Bacteria and Archaea
C. Fungi and Protista

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D. Viruses and Bacteria
Answer: B

7. What are the four main morphologies of bacteria?
A. Coccus, bacillus, vibrio, spirillum
B. Round, square, oval, spiral
C. Single, paired, clustered, chains
D. Gram-positive, gram-negative, acid-fast, non-acid-fast
Answer: A

8. Which group of microbes is noted for its ability to survive under harsh conditions?
A. Bacteria
B. Archaea
C. Fungi
D. Protista
Answer: B

9. What are the four main classifications of Eukarya?
A. Bacteria, Archaea, Fungi, Protista
B. Animalia, Plantae, Fungi, Protista
C. Prokaryotes, Eukaryotes, Viruses, Prions
D. Monera, Protista, Fungi, Plantae
Answer: B

10. Can viruses be classified as either prokaryotic or eukaryotic?
A. Yes, they are prokaryotic
B. Yes, they are eukaryotic
C. No, viruses are neither prokaryotic nor eukaryotic
D. Yes, depending on the host
Answer: C

11. The lipid bilayer of the plasma membrane is composed primarily of what?
A. Cholesterol and proteins
B. Amphipathic phospholipids with polar heads and non-polar tails
C. Carbohydrates and glycoproteins
D. Nucleic acids
Answer: B

12. How many carbon atoms are present in the monosaccharide glucose?
A. 5
B. 6
C. 7
D. 8
Answer: B

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13. What are the three main components of carbohydrates?
A. Carbon, hydrogen, oxygen
B. Carbon, hydrogen, nitrogen
C. Carbon, oxygen, phosphorus
D. Hydrogen, oxygen, nitrogen
Answer: A

14. Proteins are formed from various combinations of _____ of which there are _____
known forms.
A. Amino acids; 20
B. Nucleotides; 4
C. Fatty acids; variable
D. Monosaccharides; 6
Answer: A

15. How many amino acids are classified as being essential amino acids?
A. 5
B. 7
C. 9
D. 12
Answer: C

16. Define an essential amino acid.
A. An amino acid that the body can produce on its own
B. An amino acid that cannot be produced by the human body and must be obtained
through dietary intake
C. An amino acid that is only found in plants
D. An amino acid that is toxic in high doses
Answer: B

17. True or False: The genetic material within a prokaryotic cell is contained within a
membrane-enclosed region.
A. True
B. False
Answer: B (Prokaryotes lack a nucleus; DNA resides in the nucleoid region, which is not
membrane-bound)

18. True or False: Eukaryotic cells do not have a nucleus.
A. True
B. False
Answer: B

19. Which of the following is NOT a primary cellular organelle described in Module 1?
A. Ribosomes