Semmelweis Entrance Exam Medicine Biology Questions and
Answers Actual Exam 2026/2027 | Complete Exam-Style
Questions with Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
Section 1: Cell Biology and Cell Division
Q1: Which cellular organelle is primarily responsible for modifying, sorting, and packaging
proteins for secretion?
A. Rough endoplasmic reticulum
B. Golgi apparatus [CORRECT]
C. Lysosome
D. Peroxisome
Correct Answer: B
Rationale: The best answer is the Golgi apparatus, as it functions as the cell's post office,
receiving proteins from the endoplasmic reticulum and preparing them for transport to their
final destinations.
Q2: A red blood cell is placed in a hypertonic saline solution. What is the most likely
outcome for the cell?
A. It will swell and eventually lyse.
B. It will remain unchanged due to its rigid cell wall.
C. It will shrink as water moves out of the cell. [CORRECT]
D. It will actively pump sodium ions into the cytoplasm.
Correct Answer: C
Rationale: This choice is correct because water moves via osmosis from an area of lower
solute concentration (inside the cell) to an area of higher solute concentration (the
hypertonic solution), causing the cell to shrivel.
Q3: A mutation in the p53 gene often leads to uncontrolled cell division. What is the normal
function of the p53 protein?
A. It accelerates the transition from G1 to S phase.
B. It acts as a tumor suppressor by halting the cell cycle for DNA repair or initiating
apoptosis. [CORRECT]
C. It directly replicates mitochondrial DNA.
D. It stabilizes the mitotic spindle during metaphase.
Correct Answer: B
Rationale: This aligns with the principle that p53 is a critical checkpoint regulator; when DNA
damage is detected, it stops the cycle to allow for repairs, preventing the propagation of
mutations.
Q4: During the sodium-potassium pump cycle, how many sodium and potassium ions are
transported, and in which direction?
,A. Two sodium ions in, three potassium ions out
B. Three sodium ions out, two potassium ions in [CORRECT]
C. Three sodium ions in, two potassium ions out
D. Equal numbers of sodium and potassium ions are exchanged passively.
Correct Answer: B
Rationale: The best answer is three sodium ions out and two potassium ions in, which is the
stoichiometry required to maintain the resting membrane potential and requires ATP
hydrolysis.
Q5: Which of the following events is unique to meiosis and does not occur during mitosis?
A. Condensation of chromatin into visible chromosomes
B. Alignment of chromosomes at the metaphase plate
C. Synapsis and crossing over of homologous chromosomes [CORRECT]
D. Separation of sister chromatids
Correct Answer: C
Rationale: This matches the principle that genetic recombination through synapsis and
crossing over is a defining feature of prophase I in meiosis, promoting genetic diversity in
gametes.
Q6: Lysosomal enzymes are most active at a pH of around 5.0. What would likely happen if a
lysosomal membrane ruptured and released its contents into the cytosol?
A. The enzymes would immediately digest the entire cell.
B. The enzymes would be largely inactive due to the neutral pH of the cytosol. [CORRECT]
C. The enzymes would trigger rapid ATP synthesis.
D. The cytosolic pH would instantly drop to 5.0.
Correct Answer: B
Rationale: This choice is correct because the cytosol has a near-neutral pH (around 7.2),
which denatures or significantly reduces the activity of acid hydrolases optimized for the
acidic lysosomal environment.
Q7: A researcher treats dividing cells with Taxol, a drug that stabilizes microtubules and
prevents their depolymerization. At which stage of mitosis will the cells most likely arrest?
A. Prophase
B. Metaphase [CORRECT]
C. Telophase
D. Cytokinesis
Correct Answer: B
Rationale: The best answer is metaphase, as the inability to depolymerize microtubules
prevents the shortening of spindle fibers necessary to pull sister chromatids apart during
anaphase.
Q8: Which structure is primarily composed of rRNA and proteins, and serves as the site of
polypeptide synthesis?
A. Nucleolus
B. Ribosome [CORRECT]
C. Centrosome
D. Spliceosome
, Correct Answer: B
Rationale: This aligns with the fundamental definition of a ribosome, which reads mRNA
transcripts and catalyzes the formation of peptide bonds between amino acids.
Q9: A molecule moves across a cell membrane from an area of high concentration to an
area of low concentration with the help of a carrier protein, without the use of ATP. This
process is known as:
A. Simple diffusion
B. Active transport
C. Facilitated diffusion [CORRECT]
D. Endocytosis
Correct Answer: C
Rationale: This matches the principle that facilitated diffusion relies on transmembrane
proteins to assist the passive movement of specific molecules down their concentration
gradient.
Q10: Why do somatic cells experience progressive shortening of their chromosomes with
each division?
A. DNA polymerase cannot fully replicate the 5' end of the lagging strand. [CORRECT]
B. Telomerase is highly active in all adult somatic cells.
C. Exonucleases deliberately degrade chromosome ends after mitosis.
D. The nuclear envelope physically shears the DNA during cytokinesis.
Correct Answer: A
Rationale: The best answer is the limitation of DNA polymerase on the lagging strand, which
leaves a small gap at the 5' end of the newly synthesized strand that cannot be filled
without telomerase.
Q11: Which of the following best describes the structural composition of the plasma
membrane?
A. A rigid layer of cellulose and proteins
B. A phospholipid bilayer with embedded proteins and cholesterol [CORRECT]
C. A single layer of triglycerides surrounding the cytoplasm
D. A network of glycoproteins forming a solid barrier
Correct Answer: B
Rationale: This choice is correct because the fluid mosaic model accurately describes the
membrane as a dynamic bilayer of amphipathic phospholids interspersed with various
proteins and sterols.
Q12: A white blood cell engulfs a bacterial pathogen. This specific type of bulk transport is
called:
A. Pinocytosis
B. Receptor-mediated endocytosis
C. Phagocytosis [CORRECT]
D. Exocytosis
Correct Answer: C
Rationale: This aligns with the definition of phagocytosis, or "cell eating," where large
particulate matter is internalized via the extension of pseudopodia.
Answers Actual Exam 2026/2027 | Complete Exam-Style
Questions with Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
Section 1: Cell Biology and Cell Division
Q1: Which cellular organelle is primarily responsible for modifying, sorting, and packaging
proteins for secretion?
A. Rough endoplasmic reticulum
B. Golgi apparatus [CORRECT]
C. Lysosome
D. Peroxisome
Correct Answer: B
Rationale: The best answer is the Golgi apparatus, as it functions as the cell's post office,
receiving proteins from the endoplasmic reticulum and preparing them for transport to their
final destinations.
Q2: A red blood cell is placed in a hypertonic saline solution. What is the most likely
outcome for the cell?
A. It will swell and eventually lyse.
B. It will remain unchanged due to its rigid cell wall.
C. It will shrink as water moves out of the cell. [CORRECT]
D. It will actively pump sodium ions into the cytoplasm.
Correct Answer: C
Rationale: This choice is correct because water moves via osmosis from an area of lower
solute concentration (inside the cell) to an area of higher solute concentration (the
hypertonic solution), causing the cell to shrivel.
Q3: A mutation in the p53 gene often leads to uncontrolled cell division. What is the normal
function of the p53 protein?
A. It accelerates the transition from G1 to S phase.
B. It acts as a tumor suppressor by halting the cell cycle for DNA repair or initiating
apoptosis. [CORRECT]
C. It directly replicates mitochondrial DNA.
D. It stabilizes the mitotic spindle during metaphase.
Correct Answer: B
Rationale: This aligns with the principle that p53 is a critical checkpoint regulator; when DNA
damage is detected, it stops the cycle to allow for repairs, preventing the propagation of
mutations.
Q4: During the sodium-potassium pump cycle, how many sodium and potassium ions are
transported, and in which direction?
,A. Two sodium ions in, three potassium ions out
B. Three sodium ions out, two potassium ions in [CORRECT]
C. Three sodium ions in, two potassium ions out
D. Equal numbers of sodium and potassium ions are exchanged passively.
Correct Answer: B
Rationale: The best answer is three sodium ions out and two potassium ions in, which is the
stoichiometry required to maintain the resting membrane potential and requires ATP
hydrolysis.
Q5: Which of the following events is unique to meiosis and does not occur during mitosis?
A. Condensation of chromatin into visible chromosomes
B. Alignment of chromosomes at the metaphase plate
C. Synapsis and crossing over of homologous chromosomes [CORRECT]
D. Separation of sister chromatids
Correct Answer: C
Rationale: This matches the principle that genetic recombination through synapsis and
crossing over is a defining feature of prophase I in meiosis, promoting genetic diversity in
gametes.
Q6: Lysosomal enzymes are most active at a pH of around 5.0. What would likely happen if a
lysosomal membrane ruptured and released its contents into the cytosol?
A. The enzymes would immediately digest the entire cell.
B. The enzymes would be largely inactive due to the neutral pH of the cytosol. [CORRECT]
C. The enzymes would trigger rapid ATP synthesis.
D. The cytosolic pH would instantly drop to 5.0.
Correct Answer: B
Rationale: This choice is correct because the cytosol has a near-neutral pH (around 7.2),
which denatures or significantly reduces the activity of acid hydrolases optimized for the
acidic lysosomal environment.
Q7: A researcher treats dividing cells with Taxol, a drug that stabilizes microtubules and
prevents their depolymerization. At which stage of mitosis will the cells most likely arrest?
A. Prophase
B. Metaphase [CORRECT]
C. Telophase
D. Cytokinesis
Correct Answer: B
Rationale: The best answer is metaphase, as the inability to depolymerize microtubules
prevents the shortening of spindle fibers necessary to pull sister chromatids apart during
anaphase.
Q8: Which structure is primarily composed of rRNA and proteins, and serves as the site of
polypeptide synthesis?
A. Nucleolus
B. Ribosome [CORRECT]
C. Centrosome
D. Spliceosome
, Correct Answer: B
Rationale: This aligns with the fundamental definition of a ribosome, which reads mRNA
transcripts and catalyzes the formation of peptide bonds between amino acids.
Q9: A molecule moves across a cell membrane from an area of high concentration to an
area of low concentration with the help of a carrier protein, without the use of ATP. This
process is known as:
A. Simple diffusion
B. Active transport
C. Facilitated diffusion [CORRECT]
D. Endocytosis
Correct Answer: C
Rationale: This matches the principle that facilitated diffusion relies on transmembrane
proteins to assist the passive movement of specific molecules down their concentration
gradient.
Q10: Why do somatic cells experience progressive shortening of their chromosomes with
each division?
A. DNA polymerase cannot fully replicate the 5' end of the lagging strand. [CORRECT]
B. Telomerase is highly active in all adult somatic cells.
C. Exonucleases deliberately degrade chromosome ends after mitosis.
D. The nuclear envelope physically shears the DNA during cytokinesis.
Correct Answer: A
Rationale: The best answer is the limitation of DNA polymerase on the lagging strand, which
leaves a small gap at the 5' end of the newly synthesized strand that cannot be filled
without telomerase.
Q11: Which of the following best describes the structural composition of the plasma
membrane?
A. A rigid layer of cellulose and proteins
B. A phospholipid bilayer with embedded proteins and cholesterol [CORRECT]
C. A single layer of triglycerides surrounding the cytoplasm
D. A network of glycoproteins forming a solid barrier
Correct Answer: B
Rationale: This choice is correct because the fluid mosaic model accurately describes the
membrane as a dynamic bilayer of amphipathic phospholids interspersed with various
proteins and sterols.
Q12: A white blood cell engulfs a bacterial pathogen. This specific type of bulk transport is
called:
A. Pinocytosis
B. Receptor-mediated endocytosis
C. Phagocytosis [CORRECT]
D. Exocytosis
Correct Answer: C
Rationale: This aligns with the definition of phagocytosis, or "cell eating," where large
particulate matter is internalized via the extension of pseudopodia.
