Semmelweis Entrance Exam Medicine Biology Actual Exam 2026/2027 – Complete
Exam-Style Questions with Detailed Rationales | 100% Verified | Pass Guaranteed
– A+ Graded
Section A: Cell Biology & Organelles
Q1: A researcher observes a cell that lacks a nucleus and membrane-bound organelles
but contains ribosomes and a cell wall composed of peptidoglycan. This cell is best
classified as:
A. Eukaryotic animal cell
B. Eukaryotic plant cell
C. Prokaryotic cell [CORRECT]
D. Fungal cell
Correct Answer: C
,Rationale: Prokaryotic cells lack a nucleus and membrane-bound organelles, contain
70S ribosomes, and have peptidoglycan cell walls. Eukaryotic cells (animal, plant,
fungal) possess a nucleus and membrane-bound organelles. Plant cells have cellulose
walls, not peptidoglycan. Fungal cells have chitin walls.
Q2: Which organelle is responsible for ATP production through oxidative
phosphorylation?
A. Golgi apparatus
B. Endoplasmic reticulum
C. Mitochondria [CORRECT]
D. Lysosome
Correct Answer: C
Rationale: Mitochondria are the site of the Krebs cycle and electron transport chain,
producing ATP via oxidative phosphorylation. The Golgi apparatus modifies and
packages proteins. The ER synthesizes lipids and proteins. Lysosomes contain
hydrolytic enzymes for intracellular digestion.
Q3: The endosymbiotic theory proposes that mitochondria originated from:
,A. Invagination of the plasma membrane
B. Free-living aerobic bacteria engulfed by ancestral eukaryotic cells [CORRECT]
C. Fusion of the nuclear envelope
D. Budding from the Golgi apparatus
Correct Answer: B
Rationale: The endosymbiotic theory states that mitochondria and chloroplasts evolved
from free-living prokaryotes (aerobic bacteria and cyanobacteria, respectively) engulfed
by ancestral eukaryotic cells. Evidence includes double membranes, circular DNA, 70S
ribosomes, and independent replication. Invagination theory explains the nuclear
envelope. Golgi budding and nuclear envelope fusion are not supported by evidence.
Q4: Which cytoskeletal element is composed of actin filaments and functions in cell
movement and muscle contraction?
A. Microtubules
B. Intermediate filaments
C. Microfilaments [CORRECT]
, D. Nuclear lamina
Correct Answer: C
Rationale: Microfilaments (7 nm diameter) are composed of actin and function in cell
motility, muscle contraction, cytokinesis, and maintenance of cell shape. Microtubules
(25 nm) are composed of tubulin and function in intracellular transport and cell division.
Intermediate filaments (10 nm) provide structural support. Nuclear lamina supports the
nuclear envelope.
Q5: A patient with a genetic defect in lysosomal enzyme packaging presents with
accumulation of undigested substrates in cells. This disorder primarily affects which
organelle?
A. Mitochondria
B. Lysosomes [CORRECT]
C. Peroxisomes
D. Ribosomes
Correct Answer: B
Rationale: Lysosomes contain hydrolytic enzymes that degrade macromolecules.
Defects in lysosomal enzyme function or packaging cause lysosomal storage diseases
Exam-Style Questions with Detailed Rationales | 100% Verified | Pass Guaranteed
– A+ Graded
Section A: Cell Biology & Organelles
Q1: A researcher observes a cell that lacks a nucleus and membrane-bound organelles
but contains ribosomes and a cell wall composed of peptidoglycan. This cell is best
classified as:
A. Eukaryotic animal cell
B. Eukaryotic plant cell
C. Prokaryotic cell [CORRECT]
D. Fungal cell
Correct Answer: C
,Rationale: Prokaryotic cells lack a nucleus and membrane-bound organelles, contain
70S ribosomes, and have peptidoglycan cell walls. Eukaryotic cells (animal, plant,
fungal) possess a nucleus and membrane-bound organelles. Plant cells have cellulose
walls, not peptidoglycan. Fungal cells have chitin walls.
Q2: Which organelle is responsible for ATP production through oxidative
phosphorylation?
A. Golgi apparatus
B. Endoplasmic reticulum
C. Mitochondria [CORRECT]
D. Lysosome
Correct Answer: C
Rationale: Mitochondria are the site of the Krebs cycle and electron transport chain,
producing ATP via oxidative phosphorylation. The Golgi apparatus modifies and
packages proteins. The ER synthesizes lipids and proteins. Lysosomes contain
hydrolytic enzymes for intracellular digestion.
Q3: The endosymbiotic theory proposes that mitochondria originated from:
,A. Invagination of the plasma membrane
B. Free-living aerobic bacteria engulfed by ancestral eukaryotic cells [CORRECT]
C. Fusion of the nuclear envelope
D. Budding from the Golgi apparatus
Correct Answer: B
Rationale: The endosymbiotic theory states that mitochondria and chloroplasts evolved
from free-living prokaryotes (aerobic bacteria and cyanobacteria, respectively) engulfed
by ancestral eukaryotic cells. Evidence includes double membranes, circular DNA, 70S
ribosomes, and independent replication. Invagination theory explains the nuclear
envelope. Golgi budding and nuclear envelope fusion are not supported by evidence.
Q4: Which cytoskeletal element is composed of actin filaments and functions in cell
movement and muscle contraction?
A. Microtubules
B. Intermediate filaments
C. Microfilaments [CORRECT]
, D. Nuclear lamina
Correct Answer: C
Rationale: Microfilaments (7 nm diameter) are composed of actin and function in cell
motility, muscle contraction, cytokinesis, and maintenance of cell shape. Microtubules
(25 nm) are composed of tubulin and function in intracellular transport and cell division.
Intermediate filaments (10 nm) provide structural support. Nuclear lamina supports the
nuclear envelope.
Q5: A patient with a genetic defect in lysosomal enzyme packaging presents with
accumulation of undigested substrates in cells. This disorder primarily affects which
organelle?
A. Mitochondria
B. Lysosomes [CORRECT]
C. Peroxisomes
D. Ribosomes
Correct Answer: B
Rationale: Lysosomes contain hydrolytic enzymes that degrade macromolecules.
Defects in lysosomal enzyme function or packaging cause lysosomal storage diseases
