Multiple Choice Questions For MBBS university Exams

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MBBS First Year (CBME) – Biochemistry Paper I (November 2023)

Multiple Choice Questions with Answers and Explanations

Based on the uploaded question paper.

1. All of the following are trioses except:

A) Maltotriose
B) Glycerose
C) Dihydroxyacetone
D) Glyceraldehyde

Answer: A) Maltotriose

Explanation: Maltotriose is a trisaccharide composed of three glucose molecules, whereas glycerose, glyceraldehyde, and dihydroxyacetone are triose sugars.

2. The glycosaminoglycan without uronic acid is:

A) Dermatan sulphate
B) Keratan sulphate
C) Chondroitin sulphate
D) Heparan sulphate

Answer: B) Keratan sulphate

Explanation: Keratan sulphate is the only glycosaminoglycan that does not contain uronic acid; instead, it contains galactose.

3. Digoxin contains a sugar (glycone) and a non-sugar (aglycone) component. It is best classified as:

A) Glycoprotein
B) Glycoside
C) Oligosaccharide
D) Thioester

Answer: B) Glycoside

Explanation: A glycoside consists of a sugar linked to a non-sugar (aglycone) component.

4. A reducing sugar that is negative with glucose oxidase test is:

A) Glucose
B) Fructose
C) Maltose
D) Lactose

Answer: B) Fructose

Explanation: Fructose is a reducing sugar but is not detected by glucose oxidase, which is specific for glucose.

5. The gastric H⁺/K⁺ ATPase catalyzes which type of transport?

A) Antiport coupled transport
B) Symport coupled transport
C) Facilitated diffusion
D) Simple diffusion

Answer: A) Antiport coupled transport

Explanation: It exchanges H⁺ ions out of the cell and K⁺ ions into the cell in opposite directions.

6. Allopurinol inhibits xanthine oxidase by:

A) Suicide inhibition
B) Non-competitive inhibition
C) Allosteric activation
D) Feedback inhibition

Answer: A) Suicide inhibition

Explanation: Allopurinol is converted into oxypurinol, which irreversibly inhibits xanthine oxidase.

7. In insulin-resistant diabetes mellitus, which tissue is most affected if glucose transport is impaired?

A) RBCs
B) Muscle
C) Brain
D) Liver

Answer: B) Muscle

Explanation: Skeletal muscle depends on GLUT-4, an insulin-dependent glucose transporter.

8. Arsenic poisoning inhibits which enzyme?

A) Isocitrate dehydrogenase
B) Pyruvate dehydrogenase
C) Malate dehydrogenase
D) Succinate dehydrogenase

Answer: B) Pyruvate dehydrogenase

Explanation: Arsenic binds to lipoic acid, inhibiting the pyruvate dehydrogenase complex.

9. Which cofactor is NOT required by pyruvate dehydrogenase complex?

A) Thiamine
B) Lipoic acid
C) Pantothenate
D) Ascorbic acid

Answer: D) Ascorbic acid

Explanation: PDH requires TPP, lipoic acid, CoA, FAD, and NAD⁺, but not vitamin C.

10. Carbon monoxide poisoning inhibits:

A) Complex I of ETC
B) Cytochrome oxidase
C) ATP-ADP antiporter
D) ATP synthase

Answer: B) Cytochrome oxidase

Explanation: Carbon monoxide inhibits Complex IV (cytochrome c oxidase) of the electron transport chain.

11. Competitive inhibition of an enzyme is characterized by:

A) Km is increased
B) Km is unaltered
C) Km is decreased
D) Vmax is decreased

Answer: A) Km is increased

Explanation: Competitive inhibition increases Km while Vmax remains unchanged.

12. All are true regarding lipoprotein structure EXCEPT:

A) Phospholipid is present in the non-polar lipid core
B) TAG and cholesterol ester are present in the lipid core
C) Cholesterol is present in the amphipathic layer
D) Cholesterol ester is in the non-polar part

Answer: A) Phospholipid is present in the non-polar lipid core

Explanation: Phospholipids are present on the outer surface, not in the lipid core.

13. Chenodeoxycholic acid is used in gallstones because it:

A) Interferes with enterohepatic circulation
B) Inhibits cholesterol synthesis
C) Increases de novo bile acid production
D) Increases cholesterol solubility in bile

Answer: D) Increases cholesterol solubility in bile

Explanation: It dissolves cholesterol gallstones by increasing cholesterol solubility.

14. Which transport mechanism does NOT require energy?

A) Osmosis
B) Sodium-potassium pump
C) Simple diffusion
D) Facilitated diffusion

Answer: C) Simple diffusion

Explanation: Simple diffusion is a passive process and requires no ATP.

15. Glucose is trapped inside cells in the form of:

A) β-D-glucopyranose
B) UDP-glucose
C) Glucose-6-phosphate
D) Fructose-6-phosphate

Answer: C) Glucose-6-phosphate

Explanation: Phosphorylation of glucose prevents it from leaving the cell.

16. In anaerobic glycolysis, lactate is formed for:

A) Generation of ATP
B) Regeneration of lactate
C) Regeneration of pyruvate
D) Regeneration of NAD⁺

Answer: D) Regeneration of NAD⁺

Explanation: NAD⁺ regenerated during lactate formation is essential for continued glycolysis.

17. Fetal hemoglobin has a higher affinity for oxygen because:

A) It has higher affinity for 2,3-BPG
B) It has lower affinity for carbon monoxide
C) It has lower affinity for 2,3-BPG
D) It exists in taut structure

Answer: C) It has lower affinity for 2,3-BPG

Explanation: Reduced binding to 2,3-BPG increases oxygen affinity in fetal hemoglobin.

18. Deficiency of which vitamin causes fasting hypoglycaemia?

A) Vitamin B₆
B) Vitamin B₁₂
C) Vitamin C
D) Vitamin B₂

Answer: A) Vitamin B₆

Explanation: Vitamin B₆ is required for glycogen phosphorylase activity; deficiency impairs glycogen breakdown.

19. Atorvastatin is effective because it:

A) Stimulates phosphorylation of HMG-CoA reductase
B) Prevents intestinal cholesterol absorption
C) Prevents cholesterol deposition on arteries
D) Inhibits HMG-CoA reductase

Answer: D) Inhibits HMG-CoA reductase

Explanation: Statins reduce endogenous cholesterol synthesis by inhibiting HMG-CoA reductase.

20. Crigler–Najjar syndrome type I is caused by deficiency of:

A) Heme oxygenase
B) Biliverdin reductase
C) UDP-glucuronosyltransferase
D) Glucose-6-phosphate dehydrogenase

Answer: C) UDP-glucuronosyltransferase

Explanation: Deficiency of UDP-glucuronosyltransferase prevents bilirubin conjugation, resulting in severe unconjugated hyperbilirubinemia.

Answer Key

Q.No.AnswerQ.No.Answer
1A11A
2B12A
3B13D
4B14C
5A15C
6A16D
7B17C
8B18A
9D19D
10B20C

MBBS First Year (CBME) – Biochemistry Paper I (January 2023)

Multiple Choice Questions with Answers and Explanations

Based on the uploaded question paper.

1. Two sugars which differ from one another only in configuration around a single carbon atom are termed:

A) Anomers
B) Epimers
C) Optical isomers
D) Stereoisomers

Answer: B) Epimers

Explanation: Epimers are stereoisomers that differ in configuration at only one chiral carbon atom.

2. A 25-year-old man develops diarrhea, bloating, flatulence and frothy stools after consuming milk and dairy products. The deficient enzyme is:

A) Galactose-1-phosphate uridyl transferase
B) Fructokinase
C) Aldolase B
D) Lactase

Answer: D) Lactase

Explanation: Lactase deficiency causes lactose intolerance, leading to bloating, diarrhea, and flatulence after milk consumption.

3. All of the following are branched except:

A) Amylopectin
B) Starch
C) Amylose
D) Glycogen

Answer: C) Amylose

Explanation: Amylose is a linear polymer of glucose, whereas amylopectin and glycogen are branched.

4. Which of the following is not a lipid?

A) Glycerol
B) Palmitic acid
C) Triacylglycerol
D) Cholesterol

Answer: A) Glycerol

Explanation: Glycerol is a three-carbon alcohol and serves as the backbone of triglycerides, but it is not itself classified as a lipid.

5. Which of the following is the major lung surfactant?

A) Dipalmitoyl phosphatidylcholine
B) Phosphatidylserine
C) Phosphatidylethanolamine
D) Phosphatidylinositol

Answer: A) Dipalmitoyl phosphatidylcholine (DPPC)

Explanation: DPPC is the major pulmonary surfactant that reduces alveolar surface tension.

6. Arachidonic acid is:

A) 20:4 ω-6
B) 20:5 ω-3
C) 18:2 ω-6
D) 22:6 ω-3

Answer: A) 20:4 ω-6

Explanation: Arachidonic acid is a 20-carbon polyunsaturated omega-6 fatty acid with four double bonds.

7. Riboflavin deficiency is most likely to affect which TCA cycle enzyme?

A) Citrate synthase
B) Isocitrate dehydrogenase
C) Malate dehydrogenase
D) Succinate dehydrogenase

Answer: D) Succinate dehydrogenase

Explanation: Succinate dehydrogenase requires FAD, which is derived from riboflavin (Vitamin B₂).

8. Chylomicrons transport triacylglycerols from the intestine to:

A) Liver
B) Kidney
C) Extrahepatic tissues
D) Brain

Answer: C) Extrahepatic tissues

Explanation: Chylomicrons deliver dietary triglycerides to adipose tissue and skeletal muscle.

9. The apoprotein present in nascent chylomicrons is:

A) Apo B-100
B) Apo B-48
C) Apo C-II
D) Apo E

Answer: B) Apo B-48

Explanation: Newly formed (nascent) chylomicrons contain Apo B-48 and acquire Apo C-II and Apo E from HDL.

10. All are coenzymes of the pyruvate dehydrogenase complex except:

A) TPP
B) Biotin
C) FAD
D) NAD⁺

Answer: B) Biotin

Explanation: PDH requires TPP, lipoic acid, CoA, FAD, and NAD⁺. Biotin is not a coenzyme of PDH.

11. All the following shift the oxyhemoglobin dissociation curve to the right except:

A) Alkalosis
B) 2,3-BPG
C) Hypoxia
D) Anemia

Answer: A) Alkalosis

Explanation: Alkalosis shifts the oxygen dissociation curve to the left, increasing oxygen affinity.

12. Glycogen synthase normally functions to:

A) Remove glucose residues from glycogen
B) Transfer glucose from UDP-glucose to the non-reducing end of glycogen
C) Hydrolyze α-1,6 glycosidic bonds
D) Function as a glucosyl 4:6 transferase

Answer: B) Transfer glucose from UDP-glucose to the non-reducing end of glycogen

Explanation: Glycogen synthase elongates glycogen by adding glucose residues from UDP-glucose.

13. Propionic acid accumulation results from deficiency of which vitamin?

A) Vitamin B₆
B) Biotin
C) Folic acid
D) Vitamin B₁

Answer: B) Biotin

Explanation: Propionyl-CoA carboxylase requires biotin; deficiency leads to propionic acid accumulation.

14. The storage form of Vitamin A in mammals is:

A) Retinyl esters
B) Retinoic acid
C) Retinol
D) Beta-carotene

Answer: A) Retinyl esters

Explanation: Vitamin A is stored mainly as retinyl esters in the liver.

15. A patient consuming raw eggs develops dermatitis and glossitis. Which vitamin is deficient?

A) Biotin
B) Vitamin B₁₂
C) Folic acid
D) Niacin

Answer: A) Biotin

Explanation: Raw egg white contains avidin, which binds biotin and prevents its absorption.

16. Which is characteristic of low insulin levels?

A) Increased glycogen synthesis
B) Decreased gluconeogenesis
C) Decreased glycogenolysis
D) Increased formation of β-hydroxybutyrate

Answer: D) Increased formation of β-hydroxybutyrate

Explanation: Low insulin promotes ketogenesis, producing ketone bodies such as β-hydroxybutyrate.

17. Thiamine (Vitamin B₁) deficiency most likely causes:

A) Decreased carboxylase activity
B) Decreased serum lactate concentration
C) Decreased red blood cell transketolase activity
D) Increased urinary methylmalonate

Answer: C) Decreased red blood cell transketolase activity

Explanation: Transketolase is a thiamine-dependent enzyme; its activity decreases in thiamine deficiency.

18. Mutation of the β-hexosaminidase A gene causes:

A) Huntington disease
B) Lesch-Nyhan syndrome
C) Tay-Sachs disease
D) Amyotrophic lateral sclerosis

Answer: C) Tay-Sachs disease

Explanation: Tay-Sachs disease is caused by deficiency of β-hexosaminidase A, leading to GM₂ ganglioside accumulation.

19. The main function of chylomicrons is to:

A) Transport lipids from the liver
B) Transport dietary lipids from the intestine to target tissues
C) Transport cholesterol from IDL to LDL
D) Act as receptors for triacylglycerols in the liver

Answer: B) Transport dietary lipids from the intestine to target tissues

Explanation: Chylomicrons transport dietary triglycerides and cholesterol from the intestine to peripheral tissues.

20. Statins inhibit HMG-CoA reductase. The substrate for this enzyme is:

A) Acetoacetyl-CoA
B) HMG-CoA
C) Isopentenyl pyrophosphate
D) Mevalonate

Answer: B) HMG-CoA

Explanation: HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate, the rate-limiting step in cholesterol synthesis.

Answer Key

Q.No.AnswerQ.No.Answer
1B11A
2D12B
3C13B
4A14A
5A15A
6A16D
7D17C
8C18C
9B19B
10B20B

MBBS First Professional (CBME) – Anatomy Paper II (August 2025, Set A)

Multiple Choice Questions with Answers and Explanations

Based on the uploaded question paper (Set A).

1. Anterior ethmoidal nerve is the continuation of:

A) Frontal nerve
B) Nasociliary nerve
C) Lacrimal nerve
D) Inferior division of oculomotor nerve

Answer: B) Nasociliary nerve

Explanation: The anterior ethmoidal nerve is a terminal branch and continuation of the nasociliary nerve, a branch of the ophthalmic division (V1) of the trigeminal nerve.

2. Great cerebral vein (Vein of Galen) is formed by the union of two:

A) Internal cerebral veins
B) Anterior cerebral veins
C) Basal veins
D) Deep middle cerebral veins

Answer: A) Internal cerebral veins

Explanation: The great cerebral vein (Vein of Galen) is formed by the union of the right and left internal cerebral veins.

3. In temporomandibular joint dislocation, the joint is posteriorly related to which nerve?

A) Chorda tympani nerve
B) Masseteric nerve
C) Auriculotemporal nerve
D) Lingual nerve

Answer: C) Auriculotemporal nerve

Explanation: The auriculotemporal nerve lies posterior to the TMJ and may be affected during TMJ dislocation.

4. Which muscle separates the orbital part from the palpebral part of the lacrimal gland?

A) Superior oblique
B) Medial rectus
C) Inferior oblique
D) Levator palpebrae superioris

Answer: D) Levator palpebrae superioris

Explanation: The aponeurosis of the levator palpebrae superioris divides the lacrimal gland into orbital and palpebral parts.

5. Neostriatum is represented by:

A) Caudate nucleus and claustrum
B) Caudate nucleus and putamen
C) Putamen and globus pallidus
D) Substantia nigra

Answer: B) Caudate nucleus and putamen

Explanation: The neostriatum consists of the caudate nucleus and putamen, which are components of the basal ganglia.

6. Suprapleural membrane is attached to:

A) Transverse process of 6th cervical vertebra
B) Transverse process of 7th cervical vertebra
C) Outer border of first rib
D) Inner border of clavicle

Answer: B) Transverse process of 7th cervical vertebra

Explanation: Sibson’s fascia (suprapleural membrane) extends from the transverse process of C7 to the inner border of the first rib.

7. In an adult, the subarachnoid space ends inferiorly at:

A) Sacral promontory
B) L1
C) Coccyx
D) S2

Answer: D) S2

Explanation: The dural sac and subarachnoid space terminate at the level of the second sacral vertebra (S2).

8. Moderator band is an internal feature of the:

A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle

Answer: B) Right ventricle

Explanation: The moderator band (septomarginal trabecula) is found only in the right ventricle.

9. Which structure passes through the cavernous sinus?

A) Oculomotor nerve
B) Trochlear nerve
C) Ophthalmic nerve
D) Abducent nerve

Answer: D) Abducent nerve

Explanation: The abducent nerve (CN VI) runs within the cavernous sinus alongside the internal carotid artery.

10. Conducting tissue of the heart is a modification of:

A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardium

Answer: B) Myocardium

Explanation: The SA node, AV node, bundle of His, and Purkinje fibers are modified cardiac muscle cells.

11. Taste sensation from the anterior two-thirds of the tongue is carried by:

A) Lingual nerve
B) Chorda tympani nerve
C) Hypoglossal nerve
D) Inferior alveolar nerve

Answer: B) Chorda tympani nerve

Explanation: Taste fibers from the anterior two-thirds of the tongue are carried by the chorda tympani branch of the facial nerve.

12. The bony nasal septum is formed by:

A) Perpendicular plate of ethmoid and vomer
B) Frontal process of maxilla and nasal notch of frontal bone
C) Vomer and labyrinth of ethmoid
D) Cribriform plate of ethmoid and sphenoidal crest

Answer: A) Perpendicular plate of ethmoid and vomer

Explanation: These two bones form the major bony part of the nasal septum.

13. Pneumonia commonly affects which part of the lung?

A) Bronchi
B) Bronchioles
C) Alveoli
D) Parietal pleura

Answer: C) Alveoli

Explanation: Pneumonia is an infection of the alveoli, where inflammatory exudate accumulates.

14. External jugular vein terminates into the:

A) Internal jugular vein
B) Subclavian vein
C) Anterior jugular vein
D) Common facial vein

Answer: B) Subclavian vein

Explanation: The external jugular vein drains into the subclavian vein just above the clavicle.

15. The motor speech center (Broca’s area) corresponds to:

A) Areas 44 and 45
B) Area 40
C) Area 39
D) Area 22

Answer: A) Areas 44 and 45

Explanation: Broca’s area (Brodmann areas 44 and 45) is responsible for motor speech.

16. Tarsal (Meibomian) glands are:

A) Typical sebaceous glands
B) Typical sweat glands
C) Modified sebaceous glands
D) Modified sweat glands

Answer: C) Modified sebaceous glands

Explanation: Meibomian glands are modified sebaceous glands that secrete an oily substance to reduce tear evaporation.

17. Nerve to medial pterygoid supplies all except:

A) Medial pterygoid
B) Levator veli palatini
C) Tensor tympani
D) Tensor veli palatini

Answer: B) Levator veli palatini

Explanation: The levator veli palatini is supplied by the pharyngeal plexus (vagus nerve), not the nerve to medial pterygoid.

18. Bell’s palsy results from injury to the:

A) Vagus nerve
B) Facial nerve
C) Trigeminal nerve
D) Glossopharyngeal nerve

Answer: B) Facial nerve

Explanation: Bell’s palsy is a lower motor neuron lesion of the facial nerve (CN VII).

19. The pulmonary ligament is an extension of the:

A) Cervical pleura
B) Costal pleura
C) Mediastinal pleura
D) Diaphragmatic pleura

Answer: C) Mediastinal pleura

Explanation: The pulmonary ligament is a double fold of mediastinal pleura extending below the lung root.

20. Extradural hematoma is most commonly due to injury of the:

A) Arteries of the circle of Willis
B) Superior cerebral vein
C) Lenticulostriate artery
D) Middle meningeal artery

Answer: D) Middle meningeal artery

Explanation: Extradural (epidural) hematoma usually results from rupture of the middle meningeal artery following a temporal bone fracture.

Answer Key

Q.No.AnswerQ.No.Answer
1B11B
2A12A
3C13C
4D14B
5B15A
6B16C
7D17B
8B18B
9D19C
10B20D

MBBS First Professional (CBME) – Anatomy Paper I (August 2025, Set A)

Multiple Choice Questions with Answers and Explanations

Based on the uploaded question paper (Set A).

1. Enlargement of central group of axillary lymph nodes produces referred pain along the medial side of the arm due to compression of:

A) Axillary nerve
B) Medial cutaneous nerve of arm
C) Intercostobrachial nerve
D) Lateral cutaneous branch of 3rd intercostal nerve

Answer: C) Intercostobrachial nerve

Explanation: The intercostobrachial nerve (T2) supplies the skin of the medial arm and passes through the axilla. Enlarged axillary lymph nodes can compress it, causing referred pain.

2. In fetal life, the left umbilical vein carries oxygenated blood from the placenta to:

A) Right branch of portal vein
B) Left branch of portal vein
C) Left hepatic vein
D) Inferior vena cava

Answer: B) Left branch of portal vein

Explanation: The left umbilical vein enters the liver and joins the left branch of the portal vein before most blood passes through the ductus venosus to the inferior vena cava.

3. Which structure forms the medial boundary of Calot’s triangle?

A) Cystic duct
B) Cystic artery
C) Common hepatic duct
D) Inferior surface of liver

Answer: C) Common hepatic duct

Explanation: Calot’s triangle is bounded by the cystic duct (lateral), common hepatic duct (medial), and inferior surface of the liver (superior).

4. Rotator cuff around the shoulder joint is formed by all except:

A) Supraspinatus
B) Infraspinatus
C) Subscapularis
D) Teres major

Answer: D) Teres major

Explanation: The rotator cuff muscles are SITS: Supraspinatus, Infraspinatus, Teres minor, and Subscapularis. Teres major is not part of the rotator cuff.

5. In ruptured tubal pregnancy, the fertilized ovum is normally transferred to the uterine cavity at which stage?

A) 4-cell stage
B) 8-cell stage
C) Morula
D) Blastocyst

Answer: C) Morula

Explanation: The embryo reaches the uterine cavity approximately 3–4 days after fertilization at the morula stage.

6. At the knee, the great saphenous vein is accompanied by:

A) Medial femoral cutaneous nerve
B) Saphenous branch of descending genicular artery
C) Saphenous nerve
D) Sural nerve

Answer: C) Saphenous nerve

Explanation: The saphenous nerve accompanies the great saphenous vein along the medial side of the knee and leg.

7. Conjoint tendon is formed by the fusion of lower aponeurotic fibres of internal oblique with:

A) Transversus abdominis muscle
B) External oblique muscle
C) Transversalis fascia
D) External oblique aponeurosis

Answer: A) Transversus abdominis muscle

Explanation: The conjoint tendon (inguinal falx) is formed by the fused aponeuroses of the internal oblique and transversus abdominis muscles.

8. All of the following cells line the wall of hepatic sinusoid except:

A) Flattened endothelial cells
B) Kupffer cells
C) Natural killer cells
D) Ito cells

Answer: D) Ito cells

Explanation: Ito (stellate) cells lie in the space of Disse, not in the sinusoidal wall.

9. The unpaired branch arising from the abdominal aorta just above its bifurcation is:

A) Median sacral artery
B) Inferior mesenteric artery
C) Fourth lumbar artery
D) Testicular artery

Answer: A) Median sacral artery

Explanation: The median sacral artery arises from the posterior aspect of the abdominal aorta immediately above its bifurcation.

10. Meckel’s diverticulum is a remnant of:

A) Vitellointestinal duct
B) Allantoic diverticulum
C) Caecal bud
D) Mesonephric duct

Answer: A) Vitellointestinal duct

Explanation: Meckel’s diverticulum is the persistent proximal part of the vitellointestinal (omphalomesenteric) duct.

11. Referred pain from an ovarian cyst to the hip and knee is due to compression of:

A) Sciatic nerve
B) Femoral nerve
C) Obturator nerve
D) Genitofemoral nerve

Answer: C) Obturator nerve

Explanation: The obturator nerve supplies the medial thigh and may produce referred pain to the hip and knee when compressed by pelvic pathology.

12. The structure related to the superior border of the body of the pancreas is:

A) Splenic vein
B) Splenic artery
C) Coeliac artery
D) Right gastric artery

Answer: B) Splenic artery

Explanation: The tortuous splenic artery runs along the superior border of the pancreas.

13. A common complication of scaphoid fracture is:

A) Delayed union
B) Median nerve compression
C) Nonunion and avascular necrosis
D) Flexion deformity

Answer: C) Nonunion and avascular necrosis

Explanation: The proximal fragment of the scaphoid has a poor blood supply, predisposing it to avascular necrosis and nonunion.

14. Which structure enters the palm between the two heads of the first dorsal interosseous muscle?

A) Deep branch of ulnar artery
B) Radial artery
C) Arteria princeps pollicis
D) First dorsal metacarpal artery

Answer: B) Radial artery

Explanation: The radial artery enters the palm by passing between the two heads of the first dorsal interosseous muscle.

15. Bursitis just below the tibial tuberosity involves which bursa?

A) Subcutaneous prepatellar bursa
B) Suprapatellar bursa
C) Subcutaneous infrapatellar bursa
D) Deep infrapatellar bursa

Answer: C) Subcutaneous infrapatellar bursa

Explanation: Inflammation below the patella and over the tibial tuberosity commonly involves the subcutaneous infrapatellar bursa.

16. Which of the following is NOT a content of the spermatic cord?

A) Testicular artery
B) Artery to vas deferens
C) Cremasteric artery
D) Testicular vein

Answer: D) Testicular vein

Explanation: The spermatic cord contains the pampiniform venous plexus, not a single testicular vein.

17. Centroacinar cells are located in the:

A) Serous salivary gland
B) Submandibular gland
C) Gall bladder
D) Pancreas

Answer: D) Pancreas

Explanation: Centroacinar cells are the initial cells of the pancreatic duct system located within pancreatic acini.

18. The plantar arterial arch is completed by the:

A) Dorsalis pedis artery
B) Medial plantar artery
C) Lateral plantar artery
D) Posterior tibial artery

Answer: A) Dorsalis pedis artery

Explanation: The deep plantar branch of the dorsalis pedis artery completes the plantar arterial arch.

19. The superior suprarenal artery is a branch of the:

A) Inferior phrenic artery
B) Renal artery
C) Abdominal aorta
D) Superior mesenteric artery

Answer: A) Inferior phrenic artery

Explanation: The superior suprarenal arteries arise from the inferior phrenic arteries.

20. Which statement about the anal canal above the pectinate line is true?

A) Supplied by the superior rectal artery
B) Developed from the proctodeum
C) Supplied by somatic nerves
D) Drained into superficial inguinal lymph nodes

Answer: A) Supplied by the superior rectal artery

Explanation: The upper anal canal is derived from the hindgut, supplied by the superior rectal artery, innervated by autonomic nerves, and drains into internal iliac lymph nodes.

Answer Key

Q.No.AnswerQ.No.Answer
1C11C
2B12B
3C13C
4D14B
5C15C
6C16D
7A17D
8D18A
9A19A
10A20A

MBBS First Professional (CBME) – Anatomy Paper II (August 2025, Set A)

Multiple Choice Questions with Answers and Explanations

Based on the uploaded question paper.

1. Anterior ethmoidal nerve is the continuation of:

A) Frontal nerve
B) Nasociliary nerve
C) Lacrimal nerve
D) Inferior division of oculomotor nerve

Answer: B) Nasociliary nerve

Explanation: The anterior ethmoidal nerve is the terminal continuation of the nasociliary nerve, a branch of the ophthalmic division (V1) of the trigeminal nerve. It enters the anterior ethmoidal foramen and supplies the anterior ethmoidal air cells, nasal cavity, and external nose.

2. Great cerebral vein (Vein of Galen) is formed by the union of two:

A) Internal cerebral vein
B) Anterior cerebral vein
C) Basal vein
D) Deep middle cerebral vein

Answer: A) Internal cerebral vein

Explanation: The great cerebral vein (Vein of Galen) is formed by the union of the right and left internal cerebral veins beneath the splenium of the corpus callosum.

3. A 37-year-old man presents with inability to close his mouth. He had a history of trauma during opening his mouth. The doctor diagnosed dislocation of the temporomandibular joint. This joint is posteriorly related to which nerve?

A) Chorda tympani nerve
B) Masseteric nerve
C) Auriculotemporal nerve
D) Lingual nerve

Answer: C) Auriculotemporal nerve

Explanation: The auriculotemporal nerve lies posterior to the temporomandibular joint (TMJ). It may be compressed or injured during TMJ dislocation.

4. Name the muscle that separates the orbital part from the palpebral part of the lacrimal gland.

A) Superior oblique
B) Medial rectus
C) Inferior oblique
D) Levator palpebrae superioris

Answer: D) Levator palpebrae superioris

Explanation: The aponeurosis of the levator palpebrae superioris divides the lacrimal gland into a larger orbital part and a smaller palpebral part.

5. Neostriatum is represented by:

A) Caudate nucleus and claustrum
B) Caudate nucleus and putamen
C) Putamen and globus pallidus
D) Substantia nigra

Answer: B) Caudate nucleus and putamen

Explanation: The neostriatum is the phylogenetically newer part of the basal ganglia and consists of the caudate nucleus and putamen.

6. Suprapleural membrane is attached to:

A) Transverse process of 6th cervical vertebra
B) Transverse process of 7th cervical vertebra
C) Outer border of first rib
D) Inner border of clavicle

Answer: B) Transverse process of 7th cervical vertebra

Explanation: Sibson’s fascia (suprapleural membrane) extends from the transverse process of the seventh cervical vertebra (C7) to the inner border of the first rib.

7. In an adult, the subarachnoid space ends inferiorly at:

A) Sacral promontory
B) L1
C) Coccyx
D) S2

Answer: D) S2

Explanation: The subarachnoid space and dural sac extend down to the level of the second sacral vertebra (S2).

8. Moderator band is an internal feature of:

A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle

Answer: B) Right ventricle

Explanation: The moderator band (septomarginal trabecula) is found only in the right ventricle and carries part of the right bundle branch of the conducting system.

9. Structure which passes through the cavernous sinus is:

A) Oculomotor nerve
B) Trochlear nerve
C) Ophthalmic nerve
D) Abducent nerve

Answer: D) Abducent nerve

Explanation: The abducent nerve (CN VI) passes through the cavernous sinus alongside the internal carotid artery, whereas CN III, IV, V1, and V2 run in the lateral wall.

10. Conducting tissue of the heart is a modification of:

A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardium

Answer: B) Myocardium

Explanation: The SA node, AV node, Bundle of His, and Purkinje fibres are composed of modified cardiac muscle cells (myocardium).

11. The special sensation of anterior two-thirds of the tongue is carried by:

A) Lingual nerve
B) Chorda tympani nerve
C) Hypoglossal nerve
D) Inferior alveolar nerve

Answer: B) Chorda tympani nerve

Explanation: Taste fibres from the anterior two-thirds of the tongue travel through the chorda tympani, a branch of the facial nerve (CN VII).

12. A 31-year-old male presented with deviated nasal septum. What are the bones forming the nasal septum?

A) Perpendicular plate of ethmoid bone and vomer
B) Frontal process of maxilla and nasal notch of frontal bone
C) Vomer and labyrinthine part of ethmoid bone
D) Cribriform plate of ethmoid bone and sphenoidal crest

Answer: A) Perpendicular plate of ethmoid bone and vomer

Explanation: The bony nasal septum is mainly formed by the perpendicular plate of the ethmoid superiorly and the vomer inferiorly.

13. A patient with pneumonia commonly has infection involving which part of the lung?

A) Bronchi
B) Bronchioles
C) Alveoli
D) Parietal pleura

Answer: C) Alveoli

Explanation: Pneumonia is characterized by inflammation and consolidation of the alveoli due to accumulation of inflammatory exudate.

14. External jugular vein terminates into the:

A) Internal jugular vein
B) Subclavian vein
C) Anterior jugular vein
D) Common facial vein

Answer: B) Subclavian vein

Explanation: The external jugular vein pierces the deep fascia above the clavicle and drains into the subclavian vein.

15. A patient with motor aphasia has damage to which cortical area?

A) Area 44 and 45
B) Area 40
C) Area 39
D) Area 22

Answer: A) Area 44 and 45

Explanation: Broca’s area (Brodmann areas 44 and 45) is the motor speech centre located in the inferior frontal gyrus of the dominant hemisphere.

16. Tarsal (Meibomian) glands in the eyelids are:

A) Typical sebaceous glands
B) Typical sweat glands
C) Modified sebaceous glands
D) Modified sweat glands

Answer: C) Modified sebaceous glands

Explanation: Meibomian glands are modified sebaceous glands that secrete an oily substance to reduce evaporation of tears.

17. Nerve to medial pterygoid supplies all the following muscles except:

A) Medial pterygoid
B) Levator veli palatini
C) Tensor tympani
D) Tensor veli palatini

Answer: B) Levator veli palatini

Explanation: The nerve to medial pterygoid supplies the medial pterygoid, tensor veli palatini, and tensor tympani. Levator veli palatini is supplied by the pharyngeal plexus through the vagus nerve.

18. Bell’s palsy is due to injury of:

A) Vagus nerve
B) Facial nerve
C) Trigeminal nerve
D) Glossopharyngeal nerve

Answer: B) Facial nerve

Explanation: Bell’s palsy is a lower motor neuron paralysis of the facial nerve (CN VII), causing weakness of the muscles of facial expression.

19. The pulmonary ligament is an extension of which part of the parietal pleura?

A) Cervical pleura
B) Costal pleura
C) Mediastinal pleura
D) Diaphragmatic pleura

Answer: C) Mediastinal pleura

Explanation: The pulmonary ligament is a double layer of mediastinal pleura extending below the root of the lung.

20. A patient develops an extradural hematoma following head injury. Which artery is most commonly injured?

A) Arteries of the circle of Willis
B) Superior cerebral vein
C) Lenticulostriate artery
D) Middle meningeal artery

Answer: D) Middle meningeal artery

Explanation: Extradural (epidural) hematoma most commonly results from rupture of the middle meningeal artery, usually following fracture of the temporal bone.

Answer Key

Q.No.AnswerQ.No.Answer
1B11B
2A12A
3C13C
4D14B
5B15A
6B16C
7D17B
8B18B
9D19C
10B20D

Below are the questions with answers for SET – A from the uploaded paper. The questions are reproduced from the paper, and the answers are provided accordingly.

MBBS First Professional (CBME) – Physiology Paper I 2025

SET – A (Solved MCQs)

1. The release of hormones and neurotransmitters is an example of:

  • A) Active Transport
  • B) Vesicular Transport ✅
  • C) Facilitated Diffusion
  • D) Pinocytosis

Answer: B) Vesicular Transport

2. The indicator used for the measurement of Plasma volume is:

  • A) Inulin
  • B) Deuterium
  • C) Evans Blue ✅
  • D) Radio-labelled Chromium

Answer: C) Evans Blue

3. Resting Membrane Potential of thick Spinal motor neurons:

  • A) –30 mV
  • B) –45 mV
  • C) –90 mV ✅
  • D) Fluctuating

Answer: C) –90 mV

4. Microcytic Hypochromic Anaemia is a feature of:

  • A) Thalassemia ✅
  • B) Acute Blood loss
  • C) Pernicious anaemia
  • D) Sickle Cell anaemia

Answer: A) Thalassemia

5. 18 years old Anjali complains of recurrent painful joint swelling associated with profuse menstrual bleeding. A diagnosis of Haemophilia B was made. Coagulation abnormality seen in Haemophilia B is:

  • A) Prolonged PT
  • B) Normal PT
  • C) Normal APTT
  • D) Prolonged APTT ✅

Answer: D) Prolonged APTT

6. Which protein blocks the myosin-binding site on actin in resting skeletal muscle?

  • A) Myosin
  • B) Actin
  • C) Troponin
  • D) Tropomyosin ✅

Answer: D) Tropomyosin

7. Fast-twitch muscle fibers (Type II) are characterized by:

  • A) High myoglobin content
  • B) Slow contraction velocity
  • C) High resistance to fatigue
  • D) Anaerobic metabolism ✅

Answer: D) Anaerobic metabolism

8. Which is true about smooth muscle contraction?

  • A) Relies exclusively on troponin for calcium binding
  • B) Uses calmodulin instead of troponin ✅
  • C) Requires somatic motor nerve stimulation
  • D) Is faster than skeletal muscle contraction

Answer: B) Uses calmodulin instead of troponin

9. Sarcomere length is decided by the length of:

  • A) A band ✅
  • B) I band
  • C) H band
  • D) M line

Answer: A) A band

10. Which of the following is the correct sequence of layers in the wall of the gastrointestinal tract from inner to outer?

  • A) Submucosa → Mucosa → Muscularis externa → Serosa
  • B) Mucosa → Submucosa → Muscularis externa → Serosa ✅
  • C) Serosa → Muscularis externa → Submucosa → Mucosa
  • D) Muscularis externa → Mucosa → Serosa → Submucosa

Answer: B) Mucosa → Submucosa → Muscularis externa → Serosa

11. 18 years old Mr. Praveen complains of recurrent epigastric pain while skipping meals and taking pain killers. Which cell is responsible for secreting hydrochloric acid in the stomach?

  • A) Chief cells
  • B) G cells
  • C) Parietal cells ✅
  • D) Mucous neck cells

Answer: C) Parietal cells

12. A known alcoholic develops acute pancreatitis. Which enzyme is secreted in its active form by the pancreas?

  • A) Trypsin
  • B) Chymotrypsin
  • C) Amylase ✅
  • D) Carboxypeptidase

Answer: C) Amylase

13. The defecation reflex is initiated primarily by:

  • A) Entry of food into the stomach
  • B) Distention of the rectum ✅
  • C) Secretion of bile into the duodenum
  • D) Inhibition of sympathetic tone

Answer: B) Distention of the rectum

14. Urea recycling is crucial for:

  • A) Maintaining acid-base balance
  • B) Driving the countercurrent exchanger
  • C) Facilitating obligatory water loss
  • D) Enhancing medullary osmolarity for urine concentration ✅

Answer: D) Enhancing medullary osmolarity for urine concentration

15. The kidneys regulate extracellular fluid H⁺ concentration through all the three fundamental mechanisms except:

  • A) Direct H⁺ secretion
  • B) Bicarbonate excretion ✅
  • C) Bicarbonate reabsorption
  • D) Production of new bicarbonates

Answer: B) Bicarbonate excretion

16. A patient develops Syndrome of Inappropriate Secretion of Antidiuretic Hormone (SIADH). Which statement regarding vasopressin (ADH) is true?

  • A) It is synthesized in the posterior pituitary
  • B) It increases water reabsorption via aquaporin-1 channels
  • C) It increases blood volume by acting on the collecting ducts ✅
  • D) It increases potassium reabsorption

Answer: C) It increases blood volume by acting on the collecting ducts

17. The majority of circulating thyroid hormones in blood are:

  • A) In the free form
  • B) Bound to thyroxine-binding globulin (TBG) ✅
  • C) Bound to transthyretin
  • D) Bound to thyroxine-binding prealbumin (TBPA)

Answer: B) Bound to thyroxine-binding globulin (TBG)

18. Which organ is responsible for the final activation of Vitamin D to calcitriol (1,25-dihydroxycholecalciferol)?

  • A) Liver
  • B) Kidney ✅
  • C) Intestine
  • D) Skin

Answer: B) Kidney

19. Capacitation of sperm occurs:

  • A) In the epididymis
  • B) In the seminal vesicle
  • C) In the female genital tract ✅
  • D) Inside the seminiferous tubules

Answer: C) In the female genital tract

20. A woman with luteal phase defect is advised hCG injections. hCG maintains the corpus luteum during:

  • A) The follicular phase
  • B) The early stages of pregnancy ✅
  • C) Postmenopausal period
  • D) Menstrual phase

Answer: B) The early stages of pregnancy

Source: Questions reproduced from SET–A of the uploaded MBBS Physiology Paper I.

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