SEMMELWEIS ENTRANCE EXAM MEDICINE
BIOLOGY 2025 EXAM 300 ACTUAL QUESTIONS AND
CORRECT ANSWERS WITH RATIONALE ALREADY
GRADED A+
This comprehensive 300-question bank covers essential content for the
Semmelweis University Entrance Exam Medicine Biology section. Questions
address cell biology, molecular biology, genetics, biochemistry, human
physiology, anatomy, microbiology, immunology, endocrinology,
neurobiology, and evolution. Topics include organelle structure and function,
DNA replication, transcription, translation, enzyme kinetics, cellular
respiration, immune system components, nervous system transmission,
endocrine regulation, and reproductive biology. Each question includes a
correct answer and detailed rationale explaining the biological principles
tested in the entrance examination. The question bank progresses from
foundational concepts to advanced physiological systems, ensuring thorough
preparation without repetition of concepts or scenarios.
1. Which organelle is responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
Answer: C
Rationale: The mitochondrion is the site of oxidative phosphorylation, where
ATP is synthesized via the electron transport chain on the inner mitochondrial
membrane.
2. A cell lacks a cell wall, contains centrioles, and has small vacuoles. This cell is
most likely from which organism?
A) Oak tree
B) Mushroom
C) Bacterium
D) Human
Answer: D
, Rationale: Animal cells lack cell walls, contain centrioles, and have small
vacuoles. Plant cells have cell walls and large central vacuoles; fungal cells have
cell walls; bacteria are prokaryotic and lack membrane-bound organelles.
3. What is the primary function of ribosomes?
A) Lipid synthesis
B) Protein synthesis
C) DNA replication
D) ATP production
Answer: B
Rationale: Ribosomes synthesize proteins by translating mRNA into polypeptide
chains. Free ribosomes synthesize cytosolic proteins; bound ribosomes synthesize
proteins for secretion or membrane insertion.
4. Which cell structure is selectively permeable?
A) Cell wall
B) Cell membrane
C) Nucleus
D) Cytoplasm
Answer: B
Rationale: The cell membrane (plasma membrane) is selectively permeable,
allowing certain molecules to pass while blocking others. The cell wall is fully
permeable.
5. What is the function of lysosomes?
A) ATP production
B) Intracellular digestion and waste removal
C) Protein synthesis
D) Lipid synthesis
Answer: B
Rationale: Lysosomes contain hydrolytic enzymes that break down waste
materials, cellular debris, and foreign pathogens. They are involved in autophagy
and programmed cell death.
6. Which organelle is responsible for detoxifying harmful substances and lipid
metabolism?
A) Mitochondria
B) Ribosomes
C) Smooth endoplasmic reticulum
D) Golgi apparatus
, Answer: C
Rationale: The smooth ER synthesizes lipids, detoxifies drugs and poisons in
liver cells, and stores calcium ions. The rough ER has ribosomes and synthesizes
proteins.
7. Which of the following is found in plant cells but not animal cells?
A) Mitochondria
B) Ribosomes
C) Chloroplasts
D) Nucleus
Answer: C
Rationale: Plant cells have chloroplasts for photosynthesis, a rigid cell wall, and
large central vacuoles. Animal cells lack these structures.
8. The fluid mosaic model describes the structure of:
A) The nucleus
B) The cell membrane
C) The cell wall
D) Mitochondria
Answer: B
Rationale: The fluid mosaic model describes the cell membrane as a fluid lipid
bilayer with embedded proteins that move laterally, accounting for membrane
fluidity and protein distribution.
9. What is the function of the nucleolus?
A) DNA replication
B) rRNA synthesis and ribosome assembly
C) mRNA transcription
D) Protein synthesis
Answer: B
Rationale: The nucleolus is a dense region within the nucleus where ribosomal
RNA (rRNA) is synthesized and ribosomal subunits are assembled.
10. Which of the following is a function of the Golgi apparatus?
A) Protein synthesis
B) Modification, sorting, and packaging of proteins
C) ATP production
D) Lipid synthesis
Answer: B
, Rationale: The Golgi apparatus modifies proteins (e.g., glycosylation), sorts
them, and packages them into vesicles for transport to other organelles or
secretion.
11. What is the primary function of the cytoskeleton?
A) ATP production
B) Maintaining cell shape, movement, and transport
C) Protein synthesis
D) DNA replication
Answer: B
Rationale: The cytoskeleton maintains cell shape, enables movement, and
facilitates intracellular transport. It consists of microtubules, microfilaments, and
intermediate filaments.
12. A cell placed in a hypertonic solution will:
A) Swell and may burst
B) Shrink due to water leaving the cell
C) Remain unchanged
D) Actively transport water into the cell
Answer: B
Rationale: In a hypertonic solution, water moves out of the cell by osmosis,
causing the cell to shrink (crenation in animal cells; plasmolysis in plant cells).
13. Which base pairs with adenine (A) in DNA?
A) Guanine (G)
B) Cytosine (C)
C) Thymine (T)
D) Uracil (U)
Answer: C
Rationale: In DNA, adenine pairs with thymine via two hydrogen bonds. In
RNA, adenine pairs with uracil.
14. Which base pairs with guanine (G) in DNA?
A) Adenine (A)
B) Cytosine (C)
C) Thymine (T)
D) Uracil (U)
Answer: B
Rationale: Guanine pairs with cytosine via three hydrogen bonds. G-C pairs are
more stable than A-T pairs.
BIOLOGY 2025 EXAM 300 ACTUAL QUESTIONS AND
CORRECT ANSWERS WITH RATIONALE ALREADY
GRADED A+
This comprehensive 300-question bank covers essential content for the
Semmelweis University Entrance Exam Medicine Biology section. Questions
address cell biology, molecular biology, genetics, biochemistry, human
physiology, anatomy, microbiology, immunology, endocrinology,
neurobiology, and evolution. Topics include organelle structure and function,
DNA replication, transcription, translation, enzyme kinetics, cellular
respiration, immune system components, nervous system transmission,
endocrine regulation, and reproductive biology. Each question includes a
correct answer and detailed rationale explaining the biological principles
tested in the entrance examination. The question bank progresses from
foundational concepts to advanced physiological systems, ensuring thorough
preparation without repetition of concepts or scenarios.
1. Which organelle is responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
Answer: C
Rationale: The mitochondrion is the site of oxidative phosphorylation, where
ATP is synthesized via the electron transport chain on the inner mitochondrial
membrane.
2. A cell lacks a cell wall, contains centrioles, and has small vacuoles. This cell is
most likely from which organism?
A) Oak tree
B) Mushroom
C) Bacterium
D) Human
Answer: D
, Rationale: Animal cells lack cell walls, contain centrioles, and have small
vacuoles. Plant cells have cell walls and large central vacuoles; fungal cells have
cell walls; bacteria are prokaryotic and lack membrane-bound organelles.
3. What is the primary function of ribosomes?
A) Lipid synthesis
B) Protein synthesis
C) DNA replication
D) ATP production
Answer: B
Rationale: Ribosomes synthesize proteins by translating mRNA into polypeptide
chains. Free ribosomes synthesize cytosolic proteins; bound ribosomes synthesize
proteins for secretion or membrane insertion.
4. Which cell structure is selectively permeable?
A) Cell wall
B) Cell membrane
C) Nucleus
D) Cytoplasm
Answer: B
Rationale: The cell membrane (plasma membrane) is selectively permeable,
allowing certain molecules to pass while blocking others. The cell wall is fully
permeable.
5. What is the function of lysosomes?
A) ATP production
B) Intracellular digestion and waste removal
C) Protein synthesis
D) Lipid synthesis
Answer: B
Rationale: Lysosomes contain hydrolytic enzymes that break down waste
materials, cellular debris, and foreign pathogens. They are involved in autophagy
and programmed cell death.
6. Which organelle is responsible for detoxifying harmful substances and lipid
metabolism?
A) Mitochondria
B) Ribosomes
C) Smooth endoplasmic reticulum
D) Golgi apparatus
, Answer: C
Rationale: The smooth ER synthesizes lipids, detoxifies drugs and poisons in
liver cells, and stores calcium ions. The rough ER has ribosomes and synthesizes
proteins.
7. Which of the following is found in plant cells but not animal cells?
A) Mitochondria
B) Ribosomes
C) Chloroplasts
D) Nucleus
Answer: C
Rationale: Plant cells have chloroplasts for photosynthesis, a rigid cell wall, and
large central vacuoles. Animal cells lack these structures.
8. The fluid mosaic model describes the structure of:
A) The nucleus
B) The cell membrane
C) The cell wall
D) Mitochondria
Answer: B
Rationale: The fluid mosaic model describes the cell membrane as a fluid lipid
bilayer with embedded proteins that move laterally, accounting for membrane
fluidity and protein distribution.
9. What is the function of the nucleolus?
A) DNA replication
B) rRNA synthesis and ribosome assembly
C) mRNA transcription
D) Protein synthesis
Answer: B
Rationale: The nucleolus is a dense region within the nucleus where ribosomal
RNA (rRNA) is synthesized and ribosomal subunits are assembled.
10. Which of the following is a function of the Golgi apparatus?
A) Protein synthesis
B) Modification, sorting, and packaging of proteins
C) ATP production
D) Lipid synthesis
Answer: B
, Rationale: The Golgi apparatus modifies proteins (e.g., glycosylation), sorts
them, and packages them into vesicles for transport to other organelles or
secretion.
11. What is the primary function of the cytoskeleton?
A) ATP production
B) Maintaining cell shape, movement, and transport
C) Protein synthesis
D) DNA replication
Answer: B
Rationale: The cytoskeleton maintains cell shape, enables movement, and
facilitates intracellular transport. It consists of microtubules, microfilaments, and
intermediate filaments.
12. A cell placed in a hypertonic solution will:
A) Swell and may burst
B) Shrink due to water leaving the cell
C) Remain unchanged
D) Actively transport water into the cell
Answer: B
Rationale: In a hypertonic solution, water moves out of the cell by osmosis,
causing the cell to shrink (crenation in animal cells; plasmolysis in plant cells).
13. Which base pairs with adenine (A) in DNA?
A) Guanine (G)
B) Cytosine (C)
C) Thymine (T)
D) Uracil (U)
Answer: C
Rationale: In DNA, adenine pairs with thymine via two hydrogen bonds. In
RNA, adenine pairs with uracil.
14. Which base pairs with guanine (G) in DNA?
A) Adenine (A)
B) Cytosine (C)
C) Thymine (T)
D) Uracil (U)
Answer: B
Rationale: Guanine pairs with cytosine via three hydrogen bonds. G-C pairs are
more stable than A-T pairs.
