BIO 203 PURDUE FINAL EXAM STUDY GUIDE
2026 – COMPLETE CONCEPT REVIEW &
PRACTICE MATERIALS (LATEST EDITION)
Unit 1: Core Principles & Microscopy
1. The basic structural and functional unit of all living organisms is the:
a) Organelle
b) Tissue
c) Cell ✓
d) Biomolecule
2. Which tenet is NOT part of the modern Cell Theory?
a) All living things are composed of cells.
b) All cells arise from pre-existing cells.
c) The cell is the basic unit of life.
d) All cells have a nucleus. ✓
3. The primary factor limiting the resolution of a light microscope is the:
a) Magnification of the lenses
b) Wavelength of light ✓
c) Intensity of the light source
d) Thickness of the specimen
4. Which technique would be best to visualize the detailed 3D structure of the surface of
a cell?
a) Transmission Electron Microscopy (TEM)
b) Scanning Electron Microscopy (SEM) ✓
c) Differential Interference Contrast (DIC) Microscopy
d) Standard Brightfield Microscopy
5. Fluorescence microscopy is particularly useful because it:
a) Provides high resolution of internal organelles without staining.
b) Allows for specific labeling and tracking of particular molecules in the cell. ✓
c) Is the cheapest and easiest form of microscopy.
d) Can visualize living cells in extreme detail at the atomic level.
,Unit 2: Chemical Foundations & Biomolecules
6. A peptide bond is formed between:
a) A carboxyl group and an amino group ✓
b) Two amino groups
c) Two carboxyl groups
d) An amino group and a side chain
7. The primary structure of a protein is defined as its:
a) Overall 3D shape
b) Local alpha-helix and beta-sheet patterns
c) Unique linear sequence of amino acids ✓
d) Assembly of multiple polypeptide subunits
8. Which level of protein structure is stabilized primarily by hydrogen bonds between
backbone carbonyl and amino groups?
a) Primary
b) Secondary ✓
c) Tertiary
d) Quaternary
9. The phospholipid bilayer of a membrane is primarily held together by:
a) Covalent bonds between lipid tails
b) Hydrogen bonds between phospholipid heads
c) Hydrophobic interactions ✓
d) Ionic bonds with surrounding water
10. The difference between a purine and a pyrimidine is:
a) Purines have a double-ring structure; pyrimidines have a single ring. ✓
b) Pyrimidines are only found in DNA.
c) Purines include thymine and cytosine.
d) Pyrimidines are larger than purines.
Unit 3: Membrane Structure & Function
11. The "Fluid Mosaic Model" describes the plasma membrane as:
a) A static, rigid layer of proteins and lipids.
b) A phospholipid bilayer with proteins embedded or associated, capable of lateral
movement. ✓
c) A single layer of phospholipids covered by a protein coat.
d) A highly permeable barrier without selectivity.
,12. Cholesterol in the animal cell membrane functions primarily to:
a) Provide a source of energy for the cell.
b) Increase fluidity at low temperatures and decrease fluidity at high temperatures. ✓
c) Serve as a receptor for hormones.
d) Facilitate the transport of ions.
13. Integral membrane proteins are characterized by:
a) Being loosely attached to the surface of the membrane.
b) Having regions of hydrophobic amino acids that interact with the lipid bilayer
interior. ✓
c) Being completely soluble in the aqueous cytoplasm.
d) Only being present on the extracellular side.
14. Passive transport across a membrane:
a) Requires ATP hydrolysis.
b) Moves molecules against their concentration gradient.
c) Moves molecules down their concentration gradient. ✓
d) Always involves a protein carrier.
15. Osmosis is the diffusion of ___ across a selectively permeable membrane.
a) Solutes
b) Ions
c) Water ✓
d) Proteins
16. Facilitated diffusion differs from simple diffusion in that it:
a) Requires energy from ATP.
b) Involves specific transport proteins. ✓
c) Moves molecules against a gradient.
d) Is only for non-polar molecules.
17. The sodium-potassium pump (Na+/K+ ATPase) is a classic example of:
a) A symporter.
b) An antiporter and primary active transport. ✓
c) A passive channel.
d) Facilitated diffusion.
18. A cell placed in a hypertonic solution will:
a) Swell and possibly lyse.
b) Shrink (crenate). ✓
, c) Remain the same size.
d) Initially swell, then shrink.
Unit 4: Intracellular Compartments & Protein Sorting
19. The signal hypothesis describes how proteins destined for secretion are synthesized
by:
a) Free ribosomes in the cytoplasm.
b) Ribosomes bound to the rough ER. ✓
c) Ribosomes inside the nucleus.
d) Ribosomes attached to the Golgi.
20. A signal peptide, present at the beginning of a polypeptide chain, is recognized by:
a) A transport vesicle.
b) The Golgi apparatus.
c) A signal recognition particle (SRP). ✓
d) A lysosomal enzyme.
21. The primary function of the Golgi apparatus is:
a) ATP synthesis.
b) Protein synthesis.
c) Modification, sorting, and packaging of proteins and lipids. ✓
d) Breakdown of macromolecules.
22. Lysosomes contain:
a) Photosynthetic pigments.
b) Digestive (hydrolytic) enzymes. ✓
c) The cell's genomic DNA.
d) Ribosomes for protein synthesis.
23. Peroxisomes are organelles responsible for:
a) Protein synthesis.
b) Breaking down fatty acids and detoxifying harmful substances like hydrogen
peroxide. ✓
c) ATP production via oxidative phosphorylation.
d) Modifying glycoproteins.
24. Which organelle is the site of calcium ion storage in cells?
a) Nucleus
b) Rough ER
2026 – COMPLETE CONCEPT REVIEW &
PRACTICE MATERIALS (LATEST EDITION)
Unit 1: Core Principles & Microscopy
1. The basic structural and functional unit of all living organisms is the:
a) Organelle
b) Tissue
c) Cell ✓
d) Biomolecule
2. Which tenet is NOT part of the modern Cell Theory?
a) All living things are composed of cells.
b) All cells arise from pre-existing cells.
c) The cell is the basic unit of life.
d) All cells have a nucleus. ✓
3. The primary factor limiting the resolution of a light microscope is the:
a) Magnification of the lenses
b) Wavelength of light ✓
c) Intensity of the light source
d) Thickness of the specimen
4. Which technique would be best to visualize the detailed 3D structure of the surface of
a cell?
a) Transmission Electron Microscopy (TEM)
b) Scanning Electron Microscopy (SEM) ✓
c) Differential Interference Contrast (DIC) Microscopy
d) Standard Brightfield Microscopy
5. Fluorescence microscopy is particularly useful because it:
a) Provides high resolution of internal organelles without staining.
b) Allows for specific labeling and tracking of particular molecules in the cell. ✓
c) Is the cheapest and easiest form of microscopy.
d) Can visualize living cells in extreme detail at the atomic level.
,Unit 2: Chemical Foundations & Biomolecules
6. A peptide bond is formed between:
a) A carboxyl group and an amino group ✓
b) Two amino groups
c) Two carboxyl groups
d) An amino group and a side chain
7. The primary structure of a protein is defined as its:
a) Overall 3D shape
b) Local alpha-helix and beta-sheet patterns
c) Unique linear sequence of amino acids ✓
d) Assembly of multiple polypeptide subunits
8. Which level of protein structure is stabilized primarily by hydrogen bonds between
backbone carbonyl and amino groups?
a) Primary
b) Secondary ✓
c) Tertiary
d) Quaternary
9. The phospholipid bilayer of a membrane is primarily held together by:
a) Covalent bonds between lipid tails
b) Hydrogen bonds between phospholipid heads
c) Hydrophobic interactions ✓
d) Ionic bonds with surrounding water
10. The difference between a purine and a pyrimidine is:
a) Purines have a double-ring structure; pyrimidines have a single ring. ✓
b) Pyrimidines are only found in DNA.
c) Purines include thymine and cytosine.
d) Pyrimidines are larger than purines.
Unit 3: Membrane Structure & Function
11. The "Fluid Mosaic Model" describes the plasma membrane as:
a) A static, rigid layer of proteins and lipids.
b) A phospholipid bilayer with proteins embedded or associated, capable of lateral
movement. ✓
c) A single layer of phospholipids covered by a protein coat.
d) A highly permeable barrier without selectivity.
,12. Cholesterol in the animal cell membrane functions primarily to:
a) Provide a source of energy for the cell.
b) Increase fluidity at low temperatures and decrease fluidity at high temperatures. ✓
c) Serve as a receptor for hormones.
d) Facilitate the transport of ions.
13. Integral membrane proteins are characterized by:
a) Being loosely attached to the surface of the membrane.
b) Having regions of hydrophobic amino acids that interact with the lipid bilayer
interior. ✓
c) Being completely soluble in the aqueous cytoplasm.
d) Only being present on the extracellular side.
14. Passive transport across a membrane:
a) Requires ATP hydrolysis.
b) Moves molecules against their concentration gradient.
c) Moves molecules down their concentration gradient. ✓
d) Always involves a protein carrier.
15. Osmosis is the diffusion of ___ across a selectively permeable membrane.
a) Solutes
b) Ions
c) Water ✓
d) Proteins
16. Facilitated diffusion differs from simple diffusion in that it:
a) Requires energy from ATP.
b) Involves specific transport proteins. ✓
c) Moves molecules against a gradient.
d) Is only for non-polar molecules.
17. The sodium-potassium pump (Na+/K+ ATPase) is a classic example of:
a) A symporter.
b) An antiporter and primary active transport. ✓
c) A passive channel.
d) Facilitated diffusion.
18. A cell placed in a hypertonic solution will:
a) Swell and possibly lyse.
b) Shrink (crenate). ✓
, c) Remain the same size.
d) Initially swell, then shrink.
Unit 4: Intracellular Compartments & Protein Sorting
19. The signal hypothesis describes how proteins destined for secretion are synthesized
by:
a) Free ribosomes in the cytoplasm.
b) Ribosomes bound to the rough ER. ✓
c) Ribosomes inside the nucleus.
d) Ribosomes attached to the Golgi.
20. A signal peptide, present at the beginning of a polypeptide chain, is recognized by:
a) A transport vesicle.
b) The Golgi apparatus.
c) A signal recognition particle (SRP). ✓
d) A lysosomal enzyme.
21. The primary function of the Golgi apparatus is:
a) ATP synthesis.
b) Protein synthesis.
c) Modification, sorting, and packaging of proteins and lipids. ✓
d) Breakdown of macromolecules.
22. Lysosomes contain:
a) Photosynthetic pigments.
b) Digestive (hydrolytic) enzymes. ✓
c) The cell's genomic DNA.
d) Ribosomes for protein synthesis.
23. Peroxisomes are organelles responsible for:
a) Protein synthesis.
b) Breaking down fatty acids and detoxifying harmful substances like hydrogen
peroxide. ✓
c) ATP production via oxidative phosphorylation.
d) Modifying glycoproteins.
24. Which organelle is the site of calcium ion storage in cells?
a) Nucleus
b) Rough ER
