BIOD 171 Module 1-8 : Exam Portage Learning / Final exam Questions
and Answers 2026 Practice Set
1. Which of the following is considered a "microbe" but is not technically
classified as a "microorganism"?
A) Bacteria
B) Archaea
C) Viruses
D) Fungi
Rationale: While the terms are often used interchangeably, microorganisms must be
living organisms. Viruses are considered non-living because they cannot replicate
outside of a host cell, thus they are microbes but not microorganisms.
2. Which macromolecule is primarily responsible for the "fluid-mosaic" nature of
the plasma membrane?
A) Lipids
B) Proteins
C) Nucleic Acids
D) Carbohydrates
Rationale: Lipids, specifically phospholipids, form the bilayer that creates the physical
barrier of the cell. Their hydrophobic tails and hydrophilic heads allow the membrane to
remain fluid and semi-permeable.
3. A scientist observes a cell under a microscope and notices a distinct nucleus
and membrane-bound organelles like lysosomes. This cell is classified as:
A) Prokaryotic
B) Eukaryotic
C) Archaeon
D) Viral
Rationale: The defining characteristic of a Eukaryotic cell is the presence of a
membrane-bound nucleus and specialized organelles (like mitochondria or lysosomes),
whereas Prokaryotic cells lack a nucleus.
4. Which of the following is the smallest biological unit of life?
A) Atom
B) Molecule
C) Cell
D) Tissue
,Rationale: While atoms and molecules are smaller, the cell is the smallest unit that can
carry out all the processes of life (metabolism, reproduction, etc.) independently.
5. How many different types of amino acids are available for the cell to build
various proteins?
A) 4
B) 10
C) 20
D) 64
Rationale: There are 20 standard amino acids that serve as the monomers (building
blocks) for proteins. The specific sequence of these 20 acids determines the protein's
unique structure and function.
1. Which of the following is the smallest biological unit of life?
A) DNA
B) Atom
C) Cell
D) Organelle
Rationale: While atoms and molecules are smaller, the cell is the smallest unit that
exhibits all the characteristics of life.
2. Which of the following are considered microbes but not microorganisms?
A) Viruses
B) Bacteria
C) Fungi
D) Protozoa
Rationale: Viruses are non-living and require a host to replicate, excluding them from
the "organism" classification.
3. What is the primary function of the nucleolus?
A) Protein synthesis
B) Ribosome synthesis
C) Lipid production
D) Waste disposal
Rationale: The nucleolus is the site within the nucleus where ribosomal RNA (rRNA) is
produced and ribosomes are assembled.
4. Proteins are polymers composed of how many different amino acids?
A) 4
B) 12
,C) 20
D) 64
Rationale: There are 20 standard amino acids used by cells to build the vast variety of
proteins needed for life.
5. Which macromolecule acts as a hydrophobic barrier for the cell?
A) Carbohydrates
B) Nucleic Acids
C) Lipids
D) Proteins
Rationale: Lipids, specifically phospholipids, have hydrophobic tails that prevent
water-soluble substances from freely crossing the membrane.
6. Prokaryotic cells are characterized by the absence of:
A) A plasma membrane
B) DNA
C) A nucleus
D) Ribosomes
Rationale: Prokaryotes (like bacteria) store their DNA in a nucleoid region rather than a
membrane-bound nucleus.
7. Which organelle is known as the "powerhouse" of the cell?
A) Golgi apparatus
B) Mitochondria
C) Lysosome
D) Endoplasmic Reticulum
Rationale: Mitochondria generate ATP through cellular respiration.
8. The sugar-phosphates in DNA are held together by what type of bond?
A) Hydrogen bonds
B) Ionic bonds
C) Covalent bonds
D) Peptide bonds
Rationale: Covalent bonds provide the strong structural backbone of the DNA strand,
while hydrogen bonds hold the nitrogenous bases together.
9. Which of the following is an example of a polysaccharide?
A) Glucose
B) Lactose
C) Cellulose
D) Fructose
, Rationale: Cellulose is a complex polysaccharide used for structural support in plant
cell walls.
10. What is the primary role of the Golgi apparatus?
A) DNA replication
B) Distribution and shipping center
C) Energy production
D) Protein degradation
Rationale: The Golgi modifies, sorts, and packages proteins for secretion or delivery
to other organelles.
11. Which nitrogenous base is found in RNA but NOT in DNA?
A) Adenine
B) Thymine
C) Cytosine
D) Uracil
Rationale: RNA replaces thymine with uracil to pair with adenine.
12. Essential amino acids are those that:
A) Cannot be produced by the body and must be consumed
B) Are used to make DNA
C) Are only found in prokaryotes
D) Do not contain nitrogen
Rationale: Essential means the organism cannot synthesize them "de novo" and must
obtain them through diet.
13. A "coccus" bacterial shape is best described as:
A) Rod-shaped
B) Spherical
C) Spiral
D) Curved
Rationale: Cocci are round/spherical, while bacilli are rods.
14. What is the function of lysosomes?
A) Protein synthesis
B) Photosynthesis
C) Waste disposal/Digestion
D) Lipid storage
Rationale: Lysosomes contain digestive enzymes that break down waste materials
and cellular debris.
and Answers 2026 Practice Set
1. Which of the following is considered a "microbe" but is not technically
classified as a "microorganism"?
A) Bacteria
B) Archaea
C) Viruses
D) Fungi
Rationale: While the terms are often used interchangeably, microorganisms must be
living organisms. Viruses are considered non-living because they cannot replicate
outside of a host cell, thus they are microbes but not microorganisms.
2. Which macromolecule is primarily responsible for the "fluid-mosaic" nature of
the plasma membrane?
A) Lipids
B) Proteins
C) Nucleic Acids
D) Carbohydrates
Rationale: Lipids, specifically phospholipids, form the bilayer that creates the physical
barrier of the cell. Their hydrophobic tails and hydrophilic heads allow the membrane to
remain fluid and semi-permeable.
3. A scientist observes a cell under a microscope and notices a distinct nucleus
and membrane-bound organelles like lysosomes. This cell is classified as:
A) Prokaryotic
B) Eukaryotic
C) Archaeon
D) Viral
Rationale: The defining characteristic of a Eukaryotic cell is the presence of a
membrane-bound nucleus and specialized organelles (like mitochondria or lysosomes),
whereas Prokaryotic cells lack a nucleus.
4. Which of the following is the smallest biological unit of life?
A) Atom
B) Molecule
C) Cell
D) Tissue
,Rationale: While atoms and molecules are smaller, the cell is the smallest unit that can
carry out all the processes of life (metabolism, reproduction, etc.) independently.
5. How many different types of amino acids are available for the cell to build
various proteins?
A) 4
B) 10
C) 20
D) 64
Rationale: There are 20 standard amino acids that serve as the monomers (building
blocks) for proteins. The specific sequence of these 20 acids determines the protein's
unique structure and function.
1. Which of the following is the smallest biological unit of life?
A) DNA
B) Atom
C) Cell
D) Organelle
Rationale: While atoms and molecules are smaller, the cell is the smallest unit that
exhibits all the characteristics of life.
2. Which of the following are considered microbes but not microorganisms?
A) Viruses
B) Bacteria
C) Fungi
D) Protozoa
Rationale: Viruses are non-living and require a host to replicate, excluding them from
the "organism" classification.
3. What is the primary function of the nucleolus?
A) Protein synthesis
B) Ribosome synthesis
C) Lipid production
D) Waste disposal
Rationale: The nucleolus is the site within the nucleus where ribosomal RNA (rRNA) is
produced and ribosomes are assembled.
4. Proteins are polymers composed of how many different amino acids?
A) 4
B) 12
,C) 20
D) 64
Rationale: There are 20 standard amino acids used by cells to build the vast variety of
proteins needed for life.
5. Which macromolecule acts as a hydrophobic barrier for the cell?
A) Carbohydrates
B) Nucleic Acids
C) Lipids
D) Proteins
Rationale: Lipids, specifically phospholipids, have hydrophobic tails that prevent
water-soluble substances from freely crossing the membrane.
6. Prokaryotic cells are characterized by the absence of:
A) A plasma membrane
B) DNA
C) A nucleus
D) Ribosomes
Rationale: Prokaryotes (like bacteria) store their DNA in a nucleoid region rather than a
membrane-bound nucleus.
7. Which organelle is known as the "powerhouse" of the cell?
A) Golgi apparatus
B) Mitochondria
C) Lysosome
D) Endoplasmic Reticulum
Rationale: Mitochondria generate ATP through cellular respiration.
8. The sugar-phosphates in DNA are held together by what type of bond?
A) Hydrogen bonds
B) Ionic bonds
C) Covalent bonds
D) Peptide bonds
Rationale: Covalent bonds provide the strong structural backbone of the DNA strand,
while hydrogen bonds hold the nitrogenous bases together.
9. Which of the following is an example of a polysaccharide?
A) Glucose
B) Lactose
C) Cellulose
D) Fructose
, Rationale: Cellulose is a complex polysaccharide used for structural support in plant
cell walls.
10. What is the primary role of the Golgi apparatus?
A) DNA replication
B) Distribution and shipping center
C) Energy production
D) Protein degradation
Rationale: The Golgi modifies, sorts, and packages proteins for secretion or delivery
to other organelles.
11. Which nitrogenous base is found in RNA but NOT in DNA?
A) Adenine
B) Thymine
C) Cytosine
D) Uracil
Rationale: RNA replaces thymine with uracil to pair with adenine.
12. Essential amino acids are those that:
A) Cannot be produced by the body and must be consumed
B) Are used to make DNA
C) Are only found in prokaryotes
D) Do not contain nitrogen
Rationale: Essential means the organism cannot synthesize them "de novo" and must
obtain them through diet.
13. A "coccus" bacterial shape is best described as:
A) Rod-shaped
B) Spherical
C) Spiral
D) Curved
Rationale: Cocci are round/spherical, while bacilli are rods.
14. What is the function of lysosomes?
A) Protein synthesis
B) Photosynthesis
C) Waste disposal/Digestion
D) Lipid storage
Rationale: Lysosomes contain digestive enzymes that break down waste materials
and cellular debris.
