BIOD 171 Module 1 Exam – Essential Microbiology (Portage Learning) – 250 Practice Questions with Verified Answers

BIOD 171 Module 1 Exam – Essential Microbiology (Portage
Learning) – 250 Practice Questions with Verified Answers

QUESTIONS 1–250
Topic 1: Introduction to Microbiology


1. Microbiology is the study of:
A) All living organisms
B) Microbes (microorganisms and viruses) and their biological processes
C) Only bacteria and fungi
D) The structure of cells only
Answer B: Microbes (microorganisms and viruses) and their biological processes
Rationale: Microbiology is the study of microbes, including microorganisms and viruses, and their biological
processes.




2. Which of the following is considered a "microbe" but is NOT technically classified as a
"microorganism"?
A) Bacteria
B) Archaea
C) Viruses
D) Fungi
Answer C: Viruses
Rationale: Microorganisms must be living organisms; viruses are considered non-living because they cannot
replicate outside a host cell.




3. True or False: A virus is considered a microorganism.
A) True
B) False
Answer B: False

,Rationale: Viruses are not living organisms and do not meet the criteria of microorganisms; they are
microbes but not microorganisms.




4. What is the smallest biological unit of life?
A) Molecule
B) Atom
C) Cell
D) Tissue
Answer C: Cell
Rationale: The cell is the smallest unit capable of sustaining life processes like metabolism, growth, and
reproduction.




5. True or False: The smallest biological unit of life is the molecule.
A) True
B) False
Answer B: False
Rationale: Molecules are chemical structures that do not independently exhibit characteristics of life; the
cell is the smallest unit of life.




6. At a generalized level, all cells are comprised of what?
A) Organelles
B) Tissues
C) Macromolecules
D) Organisms
Answer C: Macromolecules
Rationale: Cells are constructed from macromolecules—proteins, lipids, nucleic acids, and polysaccharides.




7. What are the four main types of macromolecules found in cells?
A) Proteins, lipids, nucleic acids, and polysaccharides
B) Proteins, carbohydrates, vitamins, and minerals
C) Lipids, nucleic acids, enzymes, and hormones
D) Polysaccharides, proteins, water, and salts

,Answer A: Proteins, lipids, nucleic acids, and polysaccharides
Rationale: The four major classes of macromolecules are proteins, lipids, nucleic acids, and polysaccharides
(carbohydrates).




8. A macromolecule is defined as:
A) A small molecule that forms polymers
B) A complex molecule composed from smaller subunits
C) A molecule found only in viruses
D) A molecule that contains only carbon and hydrogen
Answer B: A complex molecule composed from smaller subunits
Rationale: Macromolecules are large, complex molecules made up of smaller subunits (monomers).




9. Proteins are formed from various combinations of __________, of which there are __________ known
forms.
A) Nucleotides; 4
B) Amino acids; 20
C) Monosaccharides; 6
D) Fatty acids; 10
Answer B: Amino acids; 20
Rationale: There are 20 standard amino acids that serve as the building blocks (monomers) for proteins.




10. How many amino acids are classified as being essential amino acids?
A) 4
B) 12
C) 9
D) 20
Answer C: 9
Rationale: Essential amino acids cannot be produced by the human body and must be obtained from the
diet.




11. An essential amino acid is defined as:
A) An amino acid that is found only in plants

, B) An amino acid that cannot be produced by the human body and must be taken in from the environment (e.g.,
j j j j j j j j j j j j j j j j j j j j




j food)
C) An amino acid that is not needed for protein synthesis
j j j j j j j j j j




D) An amino acid that can be synthesized by the body
j j j j j j j j j j




Answer B: An amino acid that cannot be produced by the human body and must be taken in from the
j j j j j j j j j j j j j j j j j j j




j environment (e.g., food) j j




Rationale: Essential amino acids must be obtained through diet because the body cannot synthesize them.
j j j j j j j j j j j j j j




12. How many carbon atoms are present in the monosaccharide glucose?
j j j j j j j j j j




A) 3 j




B) 4 j




C) 5 j




D) 6 j




Answer D: 6 j j




Rationale: Glucose is a six-carbon monosaccharide (C₆H₁₂O₆). j j j j j j




13. Nucleic acids are polymers composed of:
j j j j j j




A) Amino acids
j j




B) Nucleotides
j




C) Monosaccharides
j




D) Fatty acids
j j




Answer B: Nucleotides j j




Rationale: Nucleic acids (DNA and RNA) are made up of nucleotide monomers.
j j j j j j j j j j j




14. A nucleotide is composed of:
j j j j j




A) A sugar and a phosphate group
j j j j j j




B) A sugar and a nitrogenous base
j j j j j j




C) A sugar, a phosphate group, and a nitrogenous base
j j j j j j j j j




D) A phosphate group and a nitrogenous base
j j j j j j j




Answer C: A sugar, a phosphate group, and a nitrogenous base
j j j j j j j j j j




Rationale: Nucleotides consist of three components: a sugar, a phosphate group, and a nitrogenous base.
j j j j j j j j j j j j j j