ESTUDYR
BIOL 102 UPDATED EXAM WITH MOST TESTED QUESTIONS
AND ANSWERS | GRADED A+ | ASSURED SUCCESS WITH
DETAILED RATIONALES
What is the central dogma of molecular biology?
A. RNA → DNA → protein
B. Protein → DNA → RNA
C. DNA → transcription → RNA → translation → protein
D. DNA → protein → RNA
Rationale: The central dogma describes information flow: DNA is transcribed to RNA, which is
translated to protein.
Which best describes a scientific hypothesis?
A. A proven fact
B. A tentative, testable, falsifiable answer to a question
C. An untestable idea
D. A law
Rationale: A hypothesis must be testable and falsifiable.
Which best describes a scientific theory?
A. A random guess
B. A single experiment result
C. A well-substantiated, continually tested explanation
D. Synonym for hypothesis
Rationale: Theories are broad, supported explanations that integrate many observations.
Hydrogen bonds are:
A. Covalent bonds between hydrogen atoms
B. Attractions between partial charges on polar molecules
C. Ionic bonds involving hydrogen ions
D. Strongest chemical bonds
Rationale: H-bonds form between partial positive H and partial negative atoms (O, N).
Van der Waals interactions are:
A. Permanent ionic bonds
B. Weak, transient attractions from temporary partial charges
C. Covalent bonds in hydrocarbons
D. Hydrogen bonds only between water molecules
Rationale: They arise from instantaneous dipoles; individually weak, collectively important.
, ESTUDYR
How do many drugs exert effects on molecular targets?
A. By changing DNA sequence
B. By mimicking natural molecules as inhibitors or activators
C. By destroying proteins irreversibly always
D. By only binding to lipids
Rationale: Drugs often bind target sites resembling endogenous ligands.
Chemical equilibrium occurs when:
A. Only reactants remain
B. Only products remain
C. Forward and reverse reaction rates are equal
D. No molecules are moving
Rationale: At equilibrium the macroscopic concentrations stay constant.
Chemical reactions convert bonds by:
A. Only breaking bonds
B. Only making bonds
C. Making and/or breaking chemical bonds
D. Creating matter
Rationale: Reactions rearrange atoms by breaking and forming bonds.
Which property of water contributes to life?
A. Low heat capacity
B. Cohesion, ability to moderate temperature, density of ice less than liquid, universal solvent
C. Nonpolar nature
D. Hydrophobicity
Rationale: Water’s unique properties (H-bonding) enable many biological processes.
Hydrophobic vs hydrophilic molecules:
A. Hydrophobic = polar; hydrophilic = nonpolar
B. Hydrophobic = nonpolar (water-fearing); hydrophilic = polar (water-loving)
C. Both dissolve easily in water
D. Only proteins can be hydrophobic
Rationale: Polarity determines affinity for water.
An amphipathic molecule:
A. Is purely hydrophobic
B. Is purely hydrophilic
C. Has both hydrophilic and hydrophobic regions (e.g., phospholipids)
BIOL 102 UPDATED EXAM WITH MOST TESTED QUESTIONS
AND ANSWERS | GRADED A+ | ASSURED SUCCESS WITH
DETAILED RATIONALES
What is the central dogma of molecular biology?
A. RNA → DNA → protein
B. Protein → DNA → RNA
C. DNA → transcription → RNA → translation → protein
D. DNA → protein → RNA
Rationale: The central dogma describes information flow: DNA is transcribed to RNA, which is
translated to protein.
Which best describes a scientific hypothesis?
A. A proven fact
B. A tentative, testable, falsifiable answer to a question
C. An untestable idea
D. A law
Rationale: A hypothesis must be testable and falsifiable.
Which best describes a scientific theory?
A. A random guess
B. A single experiment result
C. A well-substantiated, continually tested explanation
D. Synonym for hypothesis
Rationale: Theories are broad, supported explanations that integrate many observations.
Hydrogen bonds are:
A. Covalent bonds between hydrogen atoms
B. Attractions between partial charges on polar molecules
C. Ionic bonds involving hydrogen ions
D. Strongest chemical bonds
Rationale: H-bonds form between partial positive H and partial negative atoms (O, N).
Van der Waals interactions are:
A. Permanent ionic bonds
B. Weak, transient attractions from temporary partial charges
C. Covalent bonds in hydrocarbons
D. Hydrogen bonds only between water molecules
Rationale: They arise from instantaneous dipoles; individually weak, collectively important.
, ESTUDYR
How do many drugs exert effects on molecular targets?
A. By changing DNA sequence
B. By mimicking natural molecules as inhibitors or activators
C. By destroying proteins irreversibly always
D. By only binding to lipids
Rationale: Drugs often bind target sites resembling endogenous ligands.
Chemical equilibrium occurs when:
A. Only reactants remain
B. Only products remain
C. Forward and reverse reaction rates are equal
D. No molecules are moving
Rationale: At equilibrium the macroscopic concentrations stay constant.
Chemical reactions convert bonds by:
A. Only breaking bonds
B. Only making bonds
C. Making and/or breaking chemical bonds
D. Creating matter
Rationale: Reactions rearrange atoms by breaking and forming bonds.
Which property of water contributes to life?
A. Low heat capacity
B. Cohesion, ability to moderate temperature, density of ice less than liquid, universal solvent
C. Nonpolar nature
D. Hydrophobicity
Rationale: Water’s unique properties (H-bonding) enable many biological processes.
Hydrophobic vs hydrophilic molecules:
A. Hydrophobic = polar; hydrophilic = nonpolar
B. Hydrophobic = nonpolar (water-fearing); hydrophilic = polar (water-loving)
C. Both dissolve easily in water
D. Only proteins can be hydrophobic
Rationale: Polarity determines affinity for water.
An amphipathic molecule:
A. Is purely hydrophobic
B. Is purely hydrophilic
C. Has both hydrophilic and hydrophobic regions (e.g., phospholipids)
