Mock paper Year 1 Exam- Answers
Section A (25 SBAs – A-E)
1. Which is the primary function of lysosomes?
A. Protein synthesis
B. ATP production
C. Intracellular digestion via acid hydrolases
D. DNA replication
E. Lipid synthesis
2. A defect in lysosomal enzymes most directly leads to:
A. Increased glycolysis
B. Accumulation of undegraded substrates in cells
C. Reduced ribosome formation
D. Failure of mitosis
E. Increased transcription
3. Which structure lies immediately posterior to the sternum in the anterior
mediastinum?
A. Oesophagus
B. Descending aorta
C. Thymus (especially prominent in children)
D. Vertebral column
E. Thoracic duct
4. Which checkpoint primarily ensures DNA is undamaged before entering S
phase?
A. G2/M checkpoint
B. Spindle checkpoint
C. G1/S checkpoint
D. Cytokinesis checkpoint
E. Telomere checkpoint
,5. p53 is best described as:
A. A cyclin-dependent kinase
B. A tumour suppressor transcription factor activated by DNA damage
C. A membrane receptor for growth factors
D. An anti-apoptotic mitochondrial protein
E. A DNA ligase
6. Cyclin B is most associated with progression through:
A. G1 phase
B. S phase
C. Cytokinesis only
D. G2 to M phase transition
E. G0 phase
7. Loss of p53 function most directly increases risk of cancer because:
A. DNA damage is less likely to trigger arrest/apoptosis
B. Cells cannot synthesise proteins
C. Mitochondria cannot produce ATP
D. Ribosomes fail to assemble
E. Cell membranes become unstable
8. Most lymph nodes of the axilla ultimately drain into:
A. Parasternal nodes
B. Deep cervical nodes
C. Superficial inguinal nodes
D. Popliteal nodes
E. Apical axillary nodes
9. Which structure passes through the diaphragm at the level of T10?
A. Aorta
B. Oesophagus
C. Inferior vena cava
D. Thoracic duct
E. Sympathetic trunk
10. What type of epithelium lines the normal adult oesophagus?
A. Simple squamous
B. Stratified squamous keratinised
C. Stratified squamous non-keratinised
D. Simple columnar
E. Transitional
, 11. A healthy 70 kg man has total body water ≈ 60% body weight.
Approximate extracellular fluid (ECF) volume is:
A. 7 L
B. 14 L
C. 21 L
D. 28 L
E. 42 L
12. Why does loss of retinoblastoma (Rb) protein promote uncontrolled
cell division?
A. Loss of E2F inhibition leading to S-phase
B. Increased p53 degradation
C. Increased apoptosis
D. Failure of cytokinesis
E. Reduced DNA synthesis
13. What chromosomal abnormality defines the Philadelphia
chromosome?
A.t(8;14)
B. t(9;22)
C. t(14;18)
D. t(15;17)
E. t(11;14)
14.How do tumour suppressor genes typically contribute to cancer
development?
A. Gain-of-function mutation of one allele
B. Telomerase activation alone
C. Translocation creating fusion protein
D. Increased transcription only
E. Loss-of-function mutation of both alleles
15. What immune cell is part of the innate immune system?
A. Plasma cell
B. Memory B cell
C. Neutrophil
D. CD4+ T cell
E. CD8+ T cell
Section A (25 SBAs – A-E)
1. Which is the primary function of lysosomes?
A. Protein synthesis
B. ATP production
C. Intracellular digestion via acid hydrolases
D. DNA replication
E. Lipid synthesis
2. A defect in lysosomal enzymes most directly leads to:
A. Increased glycolysis
B. Accumulation of undegraded substrates in cells
C. Reduced ribosome formation
D. Failure of mitosis
E. Increased transcription
3. Which structure lies immediately posterior to the sternum in the anterior
mediastinum?
A. Oesophagus
B. Descending aorta
C. Thymus (especially prominent in children)
D. Vertebral column
E. Thoracic duct
4. Which checkpoint primarily ensures DNA is undamaged before entering S
phase?
A. G2/M checkpoint
B. Spindle checkpoint
C. G1/S checkpoint
D. Cytokinesis checkpoint
E. Telomere checkpoint
,5. p53 is best described as:
A. A cyclin-dependent kinase
B. A tumour suppressor transcription factor activated by DNA damage
C. A membrane receptor for growth factors
D. An anti-apoptotic mitochondrial protein
E. A DNA ligase
6. Cyclin B is most associated with progression through:
A. G1 phase
B. S phase
C. Cytokinesis only
D. G2 to M phase transition
E. G0 phase
7. Loss of p53 function most directly increases risk of cancer because:
A. DNA damage is less likely to trigger arrest/apoptosis
B. Cells cannot synthesise proteins
C. Mitochondria cannot produce ATP
D. Ribosomes fail to assemble
E. Cell membranes become unstable
8. Most lymph nodes of the axilla ultimately drain into:
A. Parasternal nodes
B. Deep cervical nodes
C. Superficial inguinal nodes
D. Popliteal nodes
E. Apical axillary nodes
9. Which structure passes through the diaphragm at the level of T10?
A. Aorta
B. Oesophagus
C. Inferior vena cava
D. Thoracic duct
E. Sympathetic trunk
10. What type of epithelium lines the normal adult oesophagus?
A. Simple squamous
B. Stratified squamous keratinised
C. Stratified squamous non-keratinised
D. Simple columnar
E. Transitional
, 11. A healthy 70 kg man has total body water ≈ 60% body weight.
Approximate extracellular fluid (ECF) volume is:
A. 7 L
B. 14 L
C. 21 L
D. 28 L
E. 42 L
12. Why does loss of retinoblastoma (Rb) protein promote uncontrolled
cell division?
A. Loss of E2F inhibition leading to S-phase
B. Increased p53 degradation
C. Increased apoptosis
D. Failure of cytokinesis
E. Reduced DNA synthesis
13. What chromosomal abnormality defines the Philadelphia
chromosome?
A.t(8;14)
B. t(9;22)
C. t(14;18)
D. t(15;17)
E. t(11;14)
14.How do tumour suppressor genes typically contribute to cancer
development?
A. Gain-of-function mutation of one allele
B. Telomerase activation alone
C. Translocation creating fusion protein
D. Increased transcription only
E. Loss-of-function mutation of both alleles
15. What immune cell is part of the innate immune system?
A. Plasma cell
B. Memory B cell
C. Neutrophil
D. CD4+ T cell
E. CD8+ T cell
