A nursing student's serology after a needlestick from an unknown source is: HBsAg positive, HBeAg positive, IgM anti-HBc positive, anti-HBs negative. These results indicate:

Acute hepatitis B with high infectivity

A chronic carrier state with low infectivity

Immunity from past hepatitis B vaccination

Past infection that has fully resolved

A 22-year-old in Kochi has had fever for 2 days with headache and body ache. Dengue NS1 antigen ELISA is positive and dengue IgM is negative. How should these results be interpreted?

Acute dengue in the first days of fever

No dengue; NS1 is a non-specific test

Dengue infection some months ago

A pack placed in the centre of an overloaded autoclave grows bacteria from its spore strip, although the chamber gauge read 121 °C for 15 minutes. The most likely cause is:

Trapped air kept steam from reaching the pack

The strip was meant for a dry-heat steriliser

The cycle at 121 °C was too long for the spores

Steam at 121 °C cannot kill bacterial spores

Microbiology, pathology and genetics

25 M.Sc Nursing Entrance (AIIMS, LBS, PGIMER, JIPMER) practice questions on Microbiology, pathology and genetics, part of Basic Sciences. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A nursing student's serology after a needlestick from an unknown source is: HBsAg positive, HBeAg positive, IgM anti-HBc positive, anti-HBs negative. These results indicate:
1. AAcute hepatitis B with high infectivity
2. BA chronic carrier state with low infectivity
3. CImmunity from past hepatitis B vaccination
4. DPast infection that has fully resolved
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Answer: A · Acute hepatitis B with high infectivity
HBsAg shows that the virus is present, and IgM anti-HBc shows that the infection is recent, so this is acute hepatitis B. HBeAg reflects active viral replication and high infectivity. Anti-HBs is absent because the infection has not yet cleared. Vaccine immunity gives anti-HBs alone, and resolved infection gives anti-HBs with IgG anti-HBc and no HBsAg.
- B: A chronic carrier has IgG anti-HBc, not IgM, and low infectivity usually means HBeAg negative.
- C: Vaccination gives anti-HBs only; HBsAg would be negative.
- D: Resolved infection shows anti-HBs and no HBsAg.
Question 2 · Easy
Which infectious agent contains no nucleic acid at all?
1. APrion
2. BChlamydia
3. CMycoplasma
4. DViroid
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Answer: A · Prion
Prions are misfolded host proteins that convert normal prion protein into the abnormal form, causing diseases such as Creutzfeldt-Jakob disease. They carry no DNA or RNA. They resist routine sterilisation, so instruments used on suspected cases need extended autoclaving or strong alkali treatment. Viroids, by contrast, are naked RNA.
- B: Chlamydia is an obligate intracellular bacterium with DNA and RNA.
- C: Mycoplasma is a bacterium with both DNA and RNA.
- D: A viroid is a small naked circle of RNA.
Question 3 · Hard
A 22-year-old in Kochi has had fever for 2 days with headache and body ache. Dengue NS1 antigen ELISA is positive and dengue IgM is negative. How should these results be interpreted?
1. ANo dengue; NS1 is a non-specific test
2. BDengue infection some months ago
3. CAcute dengue in the first days of fever
4. DLate recovery phase of dengue
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Answer: C · Acute dengue in the first days of fever
NS1 is a viral protein released into the blood from the first day of fever and is detectable for about the first 5 days. IgM antibodies usually appear only from day 4-5 onwards. A positive NS1 with negative IgM on day 2 therefore means early acute dengue. The patient needs daily platelet and haematocrit monitoring, especially around defervescence, when the critical phase begins.
- A: NS1 ELISA is highly specific for dengue.
- B: Past infection would show IgG, not circulating NS1 antigen.
- D: In late recovery NS1 has gone and IgM or IgG is positive.
Question 4 · Hard
A pack placed in the centre of an overloaded autoclave grows bacteria from its spore strip, although the chamber gauge read 121 °C for 15 minutes. The most likely cause is:
1. AThe strip was meant for a dry-heat steriliser
2. BThe cycle at 121 °C was too long for the spores
3. CSteam at 121 °C cannot kill bacterial spores
4. DTrapped air kept steam from reaching the pack
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Answer: D · Trapped air kept steam from reaching the pack
Steam sterilises only where it touches surfaces. In an overpacked chamber, air pockets inside and between packs are not displaced, and air insulates far worse than steam conducts heat, so the centre never reaches sterilising conditions. The gauge reads the chamber, not the inside of the load. The load must be recalled, the steriliser loaded loosely and the cycle repeated with a new indicator.
- A: Dry-heat indicator spores are easily killed by steam, so they would show no growth.
- B: Longer exposure kills more spores, never fewer.
- C: Saturated steam at 121 °C for 15 minutes reliably kills spores when it reaches them.
Question 5 · Medium
In long-standing acid reflux, the squamous lining of the lower oesophagus is replaced by columnar epithelium. This change is called:
1. AMetaplasia
2. BDysplasia
3. CHyperplasia
4. DAnaplasia
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Answer: A · Metaplasia
Metaplasia is the reversible replacement of one adult cell type by another that copes better with the stress. In Barrett oesophagus, columnar cells resist acid better than squamous cells. However, metaplastic epithelium can progress to dysplasia and adenocarcinoma, so these patients need surveillance endoscopy. Squamous metaplasia of the bronchi in smokers is another example.
- B: Dysplasia is disordered growth with atypical cells, a later precancerous step.
- C: Hyperplasia is an increase in the number of the same cell type.
- D: Anaplasia is loss of differentiation, a feature of malignancy.
Question 6 · Easy
In about 95% of children with Down syndrome, the chromosomal cause is:
1. AMosaicism from an error after fertilisation
2. BRobertsonian translocation of chromosome 21
3. CFree trisomy 21 from meiotic non-disjunction
4. DDeletion of the short arm of chromosome 5
Answer and explanation in LearnFree account
Question 7 · Medium
A Gram stain of urethral pus from a man with acute dysuria shows many Gram-negative diplococci inside pus cells. The likely organism is:
1. ANeisseria gonorrhoeae
2. BTreponema pallidum
3. CChlamydia trachomatis
4. DHaemophilus ducreyi
Answer and explanation in LearnFree account
Question 8 · Medium
After treatment of hepatocellular carcinoma, which serum tumour marker is followed to detect recurrence?
1. AProstate-specific antigen
2. BAlpha-fetoprotein
3. CCarcinoembryonic antigen
4. DCA-125
Answer and explanation in LearnFree account
Question 9 · Hard
A 30-year-old man has a disease caused by a mutation in his mitochondrial DNA. His wife's family has no such disease. What is the risk that their children inherit his disorder?
1. AOnly the sons
2. BAlmost none of them
3. CAll of them
4. DHalf of them
Answer and explanation in LearnFree account
Question 10 · Easy
The antibody that binds to mast cells and triggers type I (immediate) hypersensitivity is:
1. AIgM
2. BIgE
3. CIgG
4. DIgA
Answer and explanation in LearnFree account
Question 11 · Medium
A man with haemophilia A marries a woman who is neither affected nor a carrier. What is the chance that any daughter of theirs is a carrier?
1. A50%
2. B0%
3. C25%
4. D100%
Answer and explanation in LearnFree account
Question 12 · Medium
Which items are correctly sterilised in a hot air oven rather than in an autoclave?
1. ACulture media and broths
2. BLiquid paraffin and talc powder
3. CDisposable plastic syringes
4. DRubber catheters and gloves
Answer and explanation in LearnFree account
Question 13 · Easy
Negri bodies seen in the brain neurons at autopsy confirm that the person died of:
1. AJapanese encephalitis
2. BHerpes simplex encephalitis
3. CNipah virus encephalitis
4. DRabies
Answer and explanation in LearnFree account
Question 14 · Medium
Caseous necrosis, a cheese-like dead tissue at the centre of granulomas, is characteristic of:
1. ATuberculosis
2. BCerebral infarction
3. CMyocardial infarction
4. DAcute pancreatitis
Answer and explanation in LearnFree account
Question 15 · Hard
A 30-year-old woman has Hb 10.4 g/dL, MCV 63 fL and red cell count 6.2 million/µL; serum ferritin is normal and HbA2 is 5.6% (normal under 3.5%). The most likely diagnosis is:
1. ABeta-thalassaemia trait
2. BIron deficiency anaemia
3. CVitamin B12 deficiency
4. DAnaemia of chronic disease
Answer and explanation in LearnFree account
Question 16 · Medium
Blood for plasma glucose that will reach the laboratory three hours later is collected in a sodium fluoride tube because fluoride:
1. AKeeps the red cells from haemolysing
2. BStops bacteria from growing in the tube
3. CPrevents the blood from clotting
4. DBlocks glycolysis by the blood cells
Answer and explanation in LearnFree account
Question 17 · Medium
Under the Spaulding classification, an indwelling urinary catheter that enters the sterile bladder must undergo:
1. ALow-level disinfection
2. BSterilisation
3. CCleaning with detergent only
4. DHigh-level disinfection
Answer and explanation in LearnFree account
Question 18 · Medium
A baby is protected against some gut infections by secretory IgA in its mother's breast milk. This type of immunity is:
1. AArtificial passive
2. BArtificial active
3. CNatural passive
4. DNatural active
Answer and explanation in LearnFree account
Question 19 · Hard
CSF from a febrile, drowsy 6-year-old is turbid: cells 1,800/µL (90% neutrophils), protein 190 mg/dL, glucose 18 mg/dL with blood glucose 110 mg/dL (normal CSF: under 5 lymphocytes/µL, protein 15-45 mg/dL, glucose about two-thirds of blood). The likely diagnosis is:
1. ACryptococcal meningitis
2. BTuberculous meningitis
3. CViral (aseptic) meningitis
4. DAcute bacterial meningitis
Answer and explanation in LearnFree account
Question 20 · Hard
Two weeks after a sore throat, an 8-year-old boy has puffy eyelids, cola-coloured urine and hypertension; serum C3 is low and ASO titre high. Which immune mechanism causes his kidney damage?
1. AType I, IgE-mediated
2. BType IV, T-cell mediated
3. CType II, cytotoxic antibody
4. DType III, immune-complex deposition
Answer and explanation in LearnFree account
Question 21 · Medium
A flexible fibreoptic endoscope cannot withstand heat. After thorough mechanical cleaning, it is best reprocessed between patients by:
1. AWiping with 70% alcohol swabs
2. BImmersion in 2% glutaraldehyde
3. CBoiling in water for 15 minutes
4. DA hot air oven at 160 °C for 2 hours
Answer and explanation in LearnFree account
Question 22 · Easy
The biological indicator used to check that a steam autoclave cycle has actually sterilised its load contains spores of:
1. ABacillus atrophaeus
2. BClostridium tetani
3. CBacillus anthracis
4. DGeobacillus stearothermophilus
Answer and explanation in LearnFree account
Question 23 · Hard
A biopsy report reads: 'Poorly differentiated squamous cell carcinoma, pT2 N1 M0'. Which part of the report gives the tumour's grade?
1. ASquamous cell carcinoma
2. BM0
3. CpT2 N1
4. DPoorly differentiated
Answer and explanation in LearnFree account
Question 24 · Easy
The single most reliable feature that marks a tumour as malignant rather than benign is:
1. AA large size at diagnosis
2. BA fast rate of growth
3. CSpread to distant sites
4. DLack of a clear capsule
Answer and explanation in LearnFree account
Question 25 · Medium
Which vaccine in India's Universal Immunisation Programme is a live attenuated bacterial vaccine?
1. AIPV
2. BPentavalent
3. CBCG
4. DTd
Answer and explanation in LearnFree account

Microbiology, pathology and genetics

A nursing student's serology after a needlestick from an unknown source is: HBsAg positive, HBeAg positive, IgM anti-HBc positive, anti-HBs negative. These results indicate:

Which infectious agent contains no nucleic acid at all?

A 22-year-old in Kochi has had fever for 2 days with headache and body ache. Dengue NS1 antigen ELISA is positive and dengue IgM is negative. How should these results be interpreted?

A pack placed in the centre of an overloaded autoclave grows bacteria from its spore strip, although the chamber gauge read 121 °C for 15 minutes. The most likely cause is:

In long-standing acid reflux, the squamous lining of the lower oesophagus is replaced by columnar epithelium. This change is called:

In about 95% of children with Down syndrome, the chromosomal cause is:

A Gram stain of urethral pus from a man with acute dysuria shows many Gram-negative diplococci inside pus cells. The likely organism is:

After treatment of hepatocellular carcinoma, which serum tumour marker is followed to detect recurrence?

A 30-year-old man has a disease caused by a mutation in his mitochondrial DNA. His wife's family has no such disease. What is the risk that their children inherit his disorder?

The antibody that binds to mast cells and triggers type I (immediate) hypersensitivity is:

A man with haemophilia A marries a woman who is neither affected nor a carrier. What is the chance that any daughter of theirs is a carrier?

Which items are correctly sterilised in a hot air oven rather than in an autoclave?

Negri bodies seen in the brain neurons at autopsy confirm that the person died of:

Caseous necrosis, a cheese-like dead tissue at the centre of granulomas, is characteristic of:

A 30-year-old woman has Hb 10.4 g/dL, MCV 63 fL and red cell count 6.2 million/µL; serum ferritin is normal and HbA2 is 5.6% (normal under 3.5%). The most likely diagnosis is:

Blood for plasma glucose that will reach the laboratory three hours later is collected in a sodium fluoride tube because fluoride:

Under the Spaulding classification, an indwelling urinary catheter that enters the sterile bladder must undergo:

A baby is protected against some gut infections by secretory IgA in its mother's breast milk. This type of immunity is:

CSF from a febrile, drowsy 6-year-old is turbid: cells 1,800/µL (90% neutrophils), protein 190 mg/dL, glucose 18 mg/dL with blood glucose 110 mg/dL (normal CSF: under 5 lymphocytes/µL, protein 15-45 mg/dL, glucose about two-thirds of blood). The likely diagnosis is:

Two weeks after a sore throat, an 8-year-old boy has puffy eyelids, cola-coloured urine and hypertension; serum C3 is low and ASO titre high. Which immune mechanism causes his kidney damage?

A flexible fibreoptic endoscope cannot withstand heat. After thorough mechanical cleaning, it is best reprocessed between patients by:

The biological indicator used to check that a steam autoclave cycle has actually sterilised its load contains spores of:

A biopsy report reads: 'Poorly differentiated squamous cell carcinoma, pT2 N1 M0'. Which part of the report gives the tumour's grade?

The single most reliable feature that marks a tumour as malignant rather than benign is:

Which vaccine in India's Universal Immunisation Programme is a live attenuated bacterial vaccine?