NEET-PG 2015 Practice Questions

Q: In water testing from a well using Horrock's apparatus, blue color appears from the 4th cup onwards. What is the amount of bleaching powder required to disinfect 75000 litres of water?

100 gm. ***100 gm*** - In **Horrock's apparatus** test, blue color appearing from the 4th cup indicates a **chlorine demand of 0.4 ppm (0.4 mg/L)** for the water sample. - **Total chlorine required** = 0.4 mg/L × 75,000 L = **30,000 mg = 30 gm** of pure chlorine. - Standard bleaching powder contains **30% available chlorine**, so: **Bleaching powder needed = 30 gm ÷ 0.30 = 100 gm**. - This is the scientifically accurate amount for disinfecting 75,000 liters of water with 0.4 ppm chlorine demand. *1000 gm* - This represents a **10-fold excess** over the actual requirement of 100 gm based on the measured chlorine demand. - Using 1000 gm would result in severe **over-chlorination** (4 ppm instead of 0.4 ppm), causing strong unpleasant taste, odor, and potential health concerns. *1600 gm* - This amount represents **16 times the required dose**, leading to dangerously high chlorine levels in the water. - Such excessive chlorination would make the water unpalatable and potentially toxic to consumers. *2000 gm* - This represents a **20-fold excess**, providing extreme and harmful over-disinfection. - Such excessive amounts could lead to **chlorine toxicity** and would be wasteful and harmful to consumers. *1300 gm* - This amount exceeds the calculated requirement by **13 times**, providing unnecessary and harmful over-disinfection. - The precise calculation based on **0.4 ppm chlorine demand** and **75,000 L volume** yields exactly **100 gm**, not 1300 gm.

Q: Which of the following is not typically used for secondary prevention of myocardial infarction?

Warfarin. ***Warfarin*** - While Warfarin is an **anticoagulant**, its primary role is in preventing *thromboembolism* in conditions like **atrial fibrillation** [1] or **mechanical heart valves**, not routinely for general **secondary prevention of MI** unless specific indications exist. - Unlike the other options, it doesn't directly address the underlying plaque rupture or reduce the workload of the heart in the typical post-MI patient. *Aspirin* - **Aspirin** is a cornerstone of secondary prevention after MI due to its **antiplatelet** effects, which help prevent future clot formation [2]. - It reduces the risk of recurrent MI, stroke, and cardiovascular death by inhibiting **platelet aggregation** [2]. *Statins* - **Statins** are crucial for secondary prevention as they aggressively lower **LDL cholesterol** levels, stabilizing existing plaques and preventing further plaque progression. - They have pleiotropic effects beyond lipid lowering, including **anti-inflammatory** and **endothelial function improvement**. *Beta blockers* - **Beta blockers** reduce myocardial oxygen demand by decreasing heart rate and contractility, which helps prevent recurrent ischemic events and improves survival post-MI [3]. - They are particularly beneficial in patients with **left ventricular dysfunction** or **hypertension** following an MI [1].

Q: Anisocoria in Horner's syndrome is due to

Disruption of the oculosympathetic pathway. ***Disruption of the oculosympathetic pathway*** - Horner's syndrome results from a lesion interrupting the **oculosympathetic pathway**, leading to classic symptoms of **miosis**, **ptosis**, and **anhidrosis** [1]. - The **miosis** (constricted pupil) specifically arises from the unopposed action of the **parasympathetic innervation** to the pupil dilatory muscles when sympathetic innervation is disrupted. *Disruption of the oculoparasympathetic pathway* - Disruption of the oculoparasympathetic pathway would result in **mydriasis** (dilated pupil), not miosis as seen in Horner's syndrome [2]. - This pathway is responsible for stimulating the **pupillary constrictor muscles**, and its disruption would lead to an inability to constrict the pupil [3]. *Disruption of the oculomotor nerve* - The **oculomotor nerve** (CN III) carries parasympathetic fibers to the eye, and its disruption typically causes a **fixed and dilated pupil** due to unopposed sympathetic action [3]. - Oculomotor nerve palsy also presents with **ptosis** and **down-and-out deviation** of the eye, which are not characteristic of isolated Horner's syndrome [1], [4]. *Disruption of the abducens nerve* - The **abducens nerve** (CN VI) solely innervates the **lateral rectus muscle**, responsible for abducting the eye. - Disruption of the abducens nerve causes **diplopia** and an inability to abduct the affected eye, with no direct impact on pupil size.

Q: The severity of mitral stenosis can be judged by-

Loud S1. ***Loud S1*** - A **loud S1** in mitral stenosis indicates that the **mitral valve leaflets are still mobile** and able to snap shut forcefully, which is characteristic of early to moderate stenosis [2]. - As mitral stenosis becomes more severe and the valve becomes calcified and rigid, the S1 sound may become diminished or even absent due to reduced leaflet mobility [1]. *Intensity of murmur* - The **intensity (loudness)** of the diastolic murmur in mitral stenosis **does not directly correlate with the severity** of the stenosis. - A loud murmur can be heard with mild stenosis, while a soft murmur in severe stenosis may be due to reduced cardiac output or left atrial pressure. *Duration of murmur* - While a **longer duration of the diastolic murmur** can coincide with more severe mitral stenosis, it is not as reliable a single indicator as other findings. - The duration is influenced by the pressure gradient across the valve and the length of diastole [2]. *Presence of left ventricular S3* - A **left ventricular S3** is typically associated with **left ventricular dysfunction** and volume overload, as seen in conditions like mitral regurgitation or dilated cardiomyopathy [3]. - It is **not a feature of mitral stenosis**, where the primary issue is obstruction to left ventricular filling.

Q: Which of the following is the MOST common condition caused by hypernatremia?

Seizure. ***Seizure*** - While not the *most* common initial symptom, **seizure** can be a severe manifestation of hypernatremia, particularly when the serum sodium levels rise rapidly or to very high concentrations leading to significant neuronal dehydration. - **Rapid correction of severe hypernatremia** can also induce seizures if the brain cells swell too quickly. *Altered mental status* - **Altered mental status** such as lethargy, confusion, or irritability, is a very common and often an earlier symptom of hypernatremia due to neuronal dehydration and intracellular water shifts, but it generally precedes more severe neurological complications like seizures.[1] - It is a broad term that encompasses a range of neurological dysfunctions, and while frequent, it is not as specific a severe endpoint as a seizure. *Brain hemorrhage* - **Brain hemorrhage** is a rare and severe complication of hypernatremia, primarily seen when extreme osmotic shifts cause significant brain shrinkage, leading to tension on bridging veins and potential rupture. - This is not a common presentation and typically occurs only in very severe cases of hypernatremia or during overly rapid correction. *Central pontine myelinosis* - **Central pontine myelinolysis (CPM)** is a neurological disorder caused by too rapid correction of *chronic hyponatremia*, not hypernatremia.[1] - It results from osmotic damage to myelin sheaths in the pons, leading to severe neurological deficits such as dysphagia, dysarthria, and even locked-in syndrome.[1]

Q: Which disease does not recur in the kidney after a renal transplant?

Alport syndrome. **Alport syndrome** * **Alport syndrome** is a genetic disorder affecting type IV collagen, primarily in the kidney; recurrence is not observed in a renal allograft because the transplanted kidney provides new, healthy type IV collagen [2]. * The disease is due to a genetic defect in the recipient's collagen genes, so the transplanted kidney, which is genetically distinct, is not susceptible to the same primary disease process [2]. *Amyloidosis* * **Amyloidosis** can recur in the transplanted kidney, as it is a systemic disease where abnormal proteins continue to deposit in various organs, including the new kidney. * The underlying cause of amyloid production is typically not cured by a kidney transplant, making the new organ vulnerable to recurrence. *Goodpasture's syndrome* * **Goodpasture's syndrome** is an autoimmune disease where antibodies target type IV collagen in the glomerular basement membrane; these autoantibodies can attack the new kidney if they are still present at the time of transplant or re-emerge [1]. * Recurrence is a significant concern, although it can often be prevented by ensuring the patient is antibody-negative before transplantation and through immunosuppression [1]. *Diabetic nephropathy (due to uncontrolled diabetes)* * **Diabetic nephropathy** almost invariably recurs in the transplanted kidney if the recipient's diabetes remains uncontrolled after transplantation. * The metabolic environment, characterized by hyperglycemia, directly contributes to the damage of the new kidney, leading to the development of diabetic nephropathy over time.

Q: What is the primary use of the freezing method in microbiology?

Preservation of microorganisms through freezing. ***Preservation of microorganisms through freezing*** - The **frozen phenomenon** or **cryopreservation** is primarily used to maintain the viability and genetic integrity of microbial cultures over long periods. - This involves rapidly freezing microorganisms, often with cryoprotectants like **glycerol** or **DMSO**, to minimize cell damage from ice crystal formation. *Sterilization of heat-sensitive materials using freezing* - Freezing is **not a reliable sterilization method** as it does not consistently kill all microbial life, especially bacterial spores. - While freezing inhibits microbial growth, it does not achieve the complete eradication required for **sterilization**. *Killing bacteria at high temperatures* - Killing bacteria at high temperatures is achieved through methods like **autoclaving** or **pasteurization**, not freezing. - High temperatures denature microbial proteins and damage cell structures, leading to cell death. *Stimulating the growth of microorganisms* - Freezing generally **inhibits microbial growth** and metabolism, putting microorganisms into a dormant state. - Growth stimulation typically involves providing optimal **nutrients, temperature, and atmospheric conditions** for replication.

Q: In which of the following conditions does Berlin's edema occur?

After concussional trauma. ***After concussional trauma*** - **Berlin's edema**, also known as **commotio retinae**, is a form of **retinal edema** that occurs following **blunt trauma** to the eye. - It results from the disruption of the **photoreceptor outer segments** and retinal pigment epithelium, leading to a **dull, gray-white appearance** of the retina. *Open angle glaucoma* - Characterized by **progressive optic nerve damage** and visual field loss, typically due to elevated intraocular pressure, without retinal edema. - The primary pathology involves the **trabecular meshwork**, not direct retinal swelling. *After cataract surgery* - A common complication is **cystoid macular edema** (Irvine-Gass syndrome), which affects the macula and can cause blurred vision. - This is distinct from Berlin's edema, as it is a **post-surgical inflammatory response**, not a direct traumatic injury. *Diabetic retinopathy* - Involves various retinal changes due to diabetes, such as **microaneurysms**, hemorrhages, and **macular edema** from leaky vessels. - It is a **metabolic and vascular disease**, not a direct consequence of acute ocular trauma.

Q: In primary open-angle glaucoma, pilocarpine eye drops lower intraocular pressure primarily by acting on which of the following?

Longitudinal fibres of the ciliary muscle. ***Longitudinal fibres of the ciliary muscle***- Pilocarpine is a **muscarinic agonist** that contracts the **longitudinal fibers of the ciliary muscle** [1, 3].- This contraction pulls on the **scleral spur**, separating the **trabecular meshwork** sheets, which increases conventional **aqueous humor outflow** [2, 3].*Trabecular meshwork*- While the **trabecular meshwork** is the site where aqueous humor exits the eye, pilocarpine primarily acts on the ciliary muscle to **indirectly affect** the meshwork's outflow facility [2, 3].- Pilocarpine does not directly alter the structure or function of the trabecular meshwork cells.*Ciliary epithelium*- The **ciliary epithelium** is responsible for **aqueous humor production** [1, 2].- Pilocarpine primarily affects **outflow**, not production, through its action on the ciliary muscle [1, 2].*All of the options*- Pilocarpine does not act on **all** these structures; its primary mechanism is through the ciliary muscle to enhance outflow.- It has no direct significant effect on **ciliary epithelium** or direct action on the **trabecular meshwork** itself.

Question 1

Which Diphtheria vaccine is recommended for a 14-year-old girl?

Accepted Answer

Tdap vaccine (Tetanus, Diphtheria, Pertussis)

Answer

DT vaccine (Diphtheria, Tetanus)

Answer

No suitable vaccine

Answer

DPT vaccine (Diphtheria, Pertussis, Tetanus)

Question 2

In water testing from a well using Horrock's apparatus, blue color appears from the 4th cup onwards. What is the amount of bleaching powder required to disinfect 75000 litres of water?

Accepted Answer

100 gm

Answer

1600 gm

Answer

2000 gm

Answer

1300 gm

Question 3

Which of the following is not typically used for secondary prevention of myocardial infarction?

Accepted Answer

Warfarin

Answer

Aspirin

Answer

Statins

Answer

Beta blockers

Question 4

Anisocoria in Horner's syndrome is due to

Accepted Answer

Disruption of the oculosympathetic pathway

Answer

Disruption of the oculoparasympathetic pathway

Answer

Disruption of the oculomotor nerve

Answer

Disruption of the abducens nerve

Question 5

The severity of mitral stenosis can be judged by-

Accepted Answer

Loud S1

Answer

Duration of murmur

Answer

Intensity of murmur

Answer

Presence of left ventricular S3

Question 6

Which of the following is the MOST common condition caused by hypernatremia?

Accepted Answer

Seizure

Answer

Altered mental status

Answer

Brain hemorrhage

Answer

Central pontine myelinosis

Question 7

Which disease does not recur in the kidney after a renal transplant?

Accepted Answer

Alport syndrome

Answer

Amyloidosis

Answer

Goodpasture's syndrome

Answer

Diabetic nephropathy (due to uncontrolled diabetes)

Question 8

What is the primary use of the freezing method in microbiology?

Accepted Answer

Preservation of microorganisms through freezing

Answer

Sterilization of heat-sensitive materials using freezing

Answer

Killing bacteria at high temperatures

Answer

Stimulating the growth of microorganisms

Question 9

In which of the following conditions does Berlin's edema occur?

Accepted Answer

After concussional trauma

Answer

Open angle glaucoma

Answer

After cataract surgery

Answer

Diabetic retinopathy

Question 10

In primary open-angle glaucoma, pilocarpine eye drops lower intraocular pressure primarily by acting on which of the following?

Accepted Answer

Longitudinal fibres of the ciliary muscle

Answer

All of the options

Answer

Trabecular meshwork

Answer

Ciliary epithelium

NEET-PG 2015

Community Medicine

Internal Medicine

Microbiology

Ophthalmology

Pharmacology