BMS 300 Exam 1 – 100 Most Tested Biomedical Science Questions with Verified
Answers & Rationales | Cell Biology, Biochemistry & Genetics Study Guide for A+
Success
Q1. Which of the following is the primary component of the cell membrane?
A) Triglycerides
B) ✓ Phospholipid bilayer
C) Cholesterol esters
D) Glycogen
The cell membrane is composed of a phospholipid bilayer with embedded proteins and
cholesterol, providing fluidity and selective permeability.
Q2. The sodium-potassium (Na⁺/K⁺) ATPase pump moves:
A) 2 Na⁺ out, 3 K⁺ in
B) ✓ 3 Na⁺ out, 2 K⁺ in
C) 3 Na⁺ in, 2 K⁺ out
D) 2 Na⁺ in, 3 K⁺ out
The Na⁺/K⁺ pump actively transports 3 sodium ions out of the cell and 2 potassium ions in,
using ATP, maintaining electrochemical gradients.
Q3. Which organelle is responsible for ATP production in eukaryotic cells?
A) Rough endoplasmic reticulum
B) Golgi apparatus
C) ✓ Mitochondria
D) Lysosome
,Mitochondria perform oxidative phosphorylation, producing the majority of ATP through the
electron transport chain and ATP synthase.
Q4. A mutation that changes a single nucleotide and results in an early stop codon is
called a:
A) Missense mutation
B) ✓ Nonsense mutation
C) Silent mutation
D) Frameshift mutation
A nonsense mutation changes a codon to a stop codon (UAA, UAG, UGA), truncating the
protein prematurely.
Q5. Which of the following bonds is strongest in an aqueous environment?
A) Hydrogen bond
B) Ionic bond
C) ✓ Covalent bond
D) Van der Waals interaction
Covalent bonds, such as peptide and phosphodiester bonds, have high bond energies and
are stable in water, unlike non-covalent interactions that are weakened by water.
Q6. Transcription in eukaryotes occurs in the:
A) Cytoplasm
B) ✓ Nucleus
C) Ribosome
D) Golgi apparatus
Transcription (DNA to mRNA) takes place in the nucleus; translation (mRNA to protein)
occurs in the cytoplasm on ribosomes.
, Q7. Which enzyme unwinds the DNA double helix during replication?
A) DNA polymerase III
B) ✓ Helicase
C) Ligase
D) Primase
Helicase breaks hydrogen bonds between base pairs, unwinding the DNA helix to form the
replication fork.
Q8. The codon AUG serves as the:
A) Stop signal
B) ✓ Start codon (methionine)
C) Promoter
D) Operator
AUG codes for methionine and is the initiation signal for protein synthesis in eukaryotes
(and bacteria, where it codes for formylmethionine).
Q9. Which of the following is not a function of the Golgi apparatus?
A) Protein sorting
B) Glycosylation
C) Lipid transport
D) ✓ Synthesis of ribosomal RNA
The Golgi modifies, sorts, and packages proteins and lipids; ribosomal RNA is synthesized
in the nucleolus.
Q10. Which process allows a cell to engulf large particles such as bacteria?
A) Pinocytosis
B) Exocytosis
C) ✓ Phagocytosis
Answers & Rationales | Cell Biology, Biochemistry & Genetics Study Guide for A+
Success
Q1. Which of the following is the primary component of the cell membrane?
A) Triglycerides
B) ✓ Phospholipid bilayer
C) Cholesterol esters
D) Glycogen
The cell membrane is composed of a phospholipid bilayer with embedded proteins and
cholesterol, providing fluidity and selective permeability.
Q2. The sodium-potassium (Na⁺/K⁺) ATPase pump moves:
A) 2 Na⁺ out, 3 K⁺ in
B) ✓ 3 Na⁺ out, 2 K⁺ in
C) 3 Na⁺ in, 2 K⁺ out
D) 2 Na⁺ in, 3 K⁺ out
The Na⁺/K⁺ pump actively transports 3 sodium ions out of the cell and 2 potassium ions in,
using ATP, maintaining electrochemical gradients.
Q3. Which organelle is responsible for ATP production in eukaryotic cells?
A) Rough endoplasmic reticulum
B) Golgi apparatus
C) ✓ Mitochondria
D) Lysosome
,Mitochondria perform oxidative phosphorylation, producing the majority of ATP through the
electron transport chain and ATP synthase.
Q4. A mutation that changes a single nucleotide and results in an early stop codon is
called a:
A) Missense mutation
B) ✓ Nonsense mutation
C) Silent mutation
D) Frameshift mutation
A nonsense mutation changes a codon to a stop codon (UAA, UAG, UGA), truncating the
protein prematurely.
Q5. Which of the following bonds is strongest in an aqueous environment?
A) Hydrogen bond
B) Ionic bond
C) ✓ Covalent bond
D) Van der Waals interaction
Covalent bonds, such as peptide and phosphodiester bonds, have high bond energies and
are stable in water, unlike non-covalent interactions that are weakened by water.
Q6. Transcription in eukaryotes occurs in the:
A) Cytoplasm
B) ✓ Nucleus
C) Ribosome
D) Golgi apparatus
Transcription (DNA to mRNA) takes place in the nucleus; translation (mRNA to protein)
occurs in the cytoplasm on ribosomes.
, Q7. Which enzyme unwinds the DNA double helix during replication?
A) DNA polymerase III
B) ✓ Helicase
C) Ligase
D) Primase
Helicase breaks hydrogen bonds between base pairs, unwinding the DNA helix to form the
replication fork.
Q8. The codon AUG serves as the:
A) Stop signal
B) ✓ Start codon (methionine)
C) Promoter
D) Operator
AUG codes for methionine and is the initiation signal for protein synthesis in eukaryotes
(and bacteria, where it codes for formylmethionine).
Q9. Which of the following is not a function of the Golgi apparatus?
A) Protein sorting
B) Glycosylation
C) Lipid transport
D) ✓ Synthesis of ribosomal RNA
The Golgi modifies, sorts, and packages proteins and lipids; ribosomal RNA is synthesized
in the nucleolus.
Q10. Which process allows a cell to engulf large particles such as bacteria?
A) Pinocytosis
B) Exocytosis
C) ✓ Phagocytosis
