MCAT (Medical College Admission Test) Latest
Updated Graded A+
Question 1 – Biology
A scientist discovers a mutation that prevents the sodium-potassium pump from functioning.
Which immediate cellular consequence is most likely?
A. Increased intracellular sodium concentration
B. Increased intracellular potassium concentration
C. Hyperpolarization of the cell membrane
D. Decreased osmotic pressure inside the cell
Answer: A. Increased intracellular sodium concentration
Rationale: The Na⁺/K⁺ ATPase normally pumps 3 Na⁺ out and 2 K⁺ in. If it fails, sodium
accumulates inside the cell, disrupting ion gradients and leading to depolarization, not
hyperpolarization.
Question 2 – Chemistry
Which of the following solutions has the lowest pH?
A. 0.01 M HCl
B. 0.01 M acetic acid (Ka = 1.8 × 10⁻⁵)
C. 0.01 M NaOH
D. 0.01 M NH₃ (Kb = 1.8 × 10⁻⁵)
Answer: A. 0.01 M HCl
Rationale: HCl is a strong acid and fully dissociates, giving [H⁺] = 0.01 M → pH ≈ 2. Acetic
acid and NH₃ are weak, so they only partially ionize. NaOH is basic.
Question 3 – Psychology/Sociology
A patient believes that strangers on the street are talking about them and plotting against them.
This is best described as:
A. Hallucination
,B. Delusion of persecution
C. Illusion
D. Delusion of grandeur
Answer: B. Delusion of persecution
Rationale: Delusions are false beliefs held despite evidence. Thinking others are plotting against
them is a persecutory delusion. Hallucinations involve sensory perception without stimulus.
Question 4 – Physics
A 2 kg block slides down a frictionless incline at 30°. What is its acceleration?
A. 4.9 m/s²
B. 9.8 m/s²
C. 2.45 m/s²
D. 19.6 m/s²
Answer: A. 4.9 m/s²
Rationale: Acceleration down an incline = g·sinθ = 9.8 × sin(30°) = 9.8 × 0.5 = 4.9 m/s².
Question 5 – Critical Analysis (CARS)
A passage argues that technological progress often outpaces ethical reflection. Which of the
following statements would most strengthen the author’s argument?
A. Ethical debates about cloning began decades after the first cloned mammal was born.
B. Scientists often publish findings in peer-reviewed journals.
C. Technology improves quality of life in most societies.
D. Ethical reflection is unnecessary in scientific progress.
Answer: A. Ethical debates about cloning began decades after the first cloned mammal was
born.
Rationale: This directly supports the claim that ethics lag behind technology. The other options
either weaken or are irrelevant.
, Biology & Biochemistry
Q6. Which organelle is primarily responsible for protein glycosylation?
A. Nucleus
B. Golgi apparatus
C. Mitochondria
D. Lysosome
Answer: B. Golgi apparatus
Rationale: The Golgi modifies proteins post-translationally, including glycosylation.
Q7. Which enzyme is responsible for unwinding DNA during replication?
A. DNA polymerase
B. Helicase
C. Ligase
D. Primase
Answer: B. Helicase
Rationale: Helicase unwinds the double helix, allowing replication machinery to access strands.
Q8. A mutation prevents hemoglobin from binding oxygen efficiently. Which physiological
change occurs?
A. Increased tissue oxygen delivery
B. Decreased oxygen saturation in blood
C. Increased affinity for oxygen
D. Decreased CO₂ transport
Answer: B. Decreased oxygen saturation in blood
Rationale: Hemoglobin’s reduced binding lowers oxygen saturation.
Q9. Which metabolic pathway occurs in the cytoplasm?
Updated Graded A+
Question 1 – Biology
A scientist discovers a mutation that prevents the sodium-potassium pump from functioning.
Which immediate cellular consequence is most likely?
A. Increased intracellular sodium concentration
B. Increased intracellular potassium concentration
C. Hyperpolarization of the cell membrane
D. Decreased osmotic pressure inside the cell
Answer: A. Increased intracellular sodium concentration
Rationale: The Na⁺/K⁺ ATPase normally pumps 3 Na⁺ out and 2 K⁺ in. If it fails, sodium
accumulates inside the cell, disrupting ion gradients and leading to depolarization, not
hyperpolarization.
Question 2 – Chemistry
Which of the following solutions has the lowest pH?
A. 0.01 M HCl
B. 0.01 M acetic acid (Ka = 1.8 × 10⁻⁵)
C. 0.01 M NaOH
D. 0.01 M NH₃ (Kb = 1.8 × 10⁻⁵)
Answer: A. 0.01 M HCl
Rationale: HCl is a strong acid and fully dissociates, giving [H⁺] = 0.01 M → pH ≈ 2. Acetic
acid and NH₃ are weak, so they only partially ionize. NaOH is basic.
Question 3 – Psychology/Sociology
A patient believes that strangers on the street are talking about them and plotting against them.
This is best described as:
A. Hallucination
,B. Delusion of persecution
C. Illusion
D. Delusion of grandeur
Answer: B. Delusion of persecution
Rationale: Delusions are false beliefs held despite evidence. Thinking others are plotting against
them is a persecutory delusion. Hallucinations involve sensory perception without stimulus.
Question 4 – Physics
A 2 kg block slides down a frictionless incline at 30°. What is its acceleration?
A. 4.9 m/s²
B. 9.8 m/s²
C. 2.45 m/s²
D. 19.6 m/s²
Answer: A. 4.9 m/s²
Rationale: Acceleration down an incline = g·sinθ = 9.8 × sin(30°) = 9.8 × 0.5 = 4.9 m/s².
Question 5 – Critical Analysis (CARS)
A passage argues that technological progress often outpaces ethical reflection. Which of the
following statements would most strengthen the author’s argument?
A. Ethical debates about cloning began decades after the first cloned mammal was born.
B. Scientists often publish findings in peer-reviewed journals.
C. Technology improves quality of life in most societies.
D. Ethical reflection is unnecessary in scientific progress.
Answer: A. Ethical debates about cloning began decades after the first cloned mammal was
born.
Rationale: This directly supports the claim that ethics lag behind technology. The other options
either weaken or are irrelevant.
, Biology & Biochemistry
Q6. Which organelle is primarily responsible for protein glycosylation?
A. Nucleus
B. Golgi apparatus
C. Mitochondria
D. Lysosome
Answer: B. Golgi apparatus
Rationale: The Golgi modifies proteins post-translationally, including glycosylation.
Q7. Which enzyme is responsible for unwinding DNA during replication?
A. DNA polymerase
B. Helicase
C. Ligase
D. Primase
Answer: B. Helicase
Rationale: Helicase unwinds the double helix, allowing replication machinery to access strands.
Q8. A mutation prevents hemoglobin from binding oxygen efficiently. Which physiological
change occurs?
A. Increased tissue oxygen delivery
B. Decreased oxygen saturation in blood
C. Increased affinity for oxygen
D. Decreased CO₂ transport
Answer: B. Decreased oxygen saturation in blood
Rationale: Hemoglobin’s reduced binding lowers oxygen saturation.
Q9. Which metabolic pathway occurs in the cytoplasm?
