NEET-PG 2012 Practice Questions

Q: Which graphical representation is best suited for depicting continuous quantitative data?

Histogram. **Histogram** - A **histogram** is specifically designed for depicting the distribution of **continuous quantitative data** by dividing the data into bins and showing the frequency of data points within each bin. - The bars in a histogram are adjacent, indicating the continuous nature of the data and representing ranges of values. *Bar diagram* - A **bar diagram** (or bar chart) is typically used for comparing **discrete categories** or displaying changes over time for categorical data. - The bars in a bar diagram are usually separated, emphasizing distinct categories rather than continuous ranges. *Pie chart* - A **pie chart** is used to show the **proportions of a whole**, representing parts of a composition for categorical data. - It is not suitable for continuous data as it provides no information about the distribution or frequency across a range of values. *Pictogram* - A **pictogram** uses images or icons to represent data, making it visually engaging, but it is generally used for **simple comparisons of discrete or categorical data**. - It lacks the precision and detail required to accurately depict the distribution or frequency of continuous quantitative data.

Q: Coxsackie virus is classified as which type of virus?

Enterovirus. ***Enterovirus*** - **Coxsackie virus** belongs to the genus *Enterovirus* within the family *Picornaviridae*. - Enteroviruses are characterized as **non-enveloped, positive-sense, single-stranded RNA viruses** and typically infect the gastrointestinal tract. *Herpes virus* - Herpes viruses are **enveloped, double-stranded DNA viruses** known for causing latent infections. - Examples include HSV-1 (oral herpes) and VZV (chickenpox), which are distinct from Coxsackie. *Pox virus* - Pox viruses are **large, enveloped, double-stranded DNA viruses** that replicate in the cytoplasm of infected cells. - Smallpox and molluscum contagiosum are caused by pox viruses, which have different genetic and structural characteristics than Coxsackie virus. *Myxovirus* - **Myxovirus** is an older classification that once included viruses now categorized into *Orthomyxoviridae* (e.g., influenza) and *Paramyxoviridae* (e.g., measles, mumps). - These are **enveloped, negative-sense, single-stranded RNA viruses**, a different viral structure and replication strategy compared to Coxsackie virus.

Q: Which of the following statements about corneal dystrophy is true?

It is typically bilateral.. ***It is typically bilateral.*** - **Corneal dystrophies** are inherited genetic disorders that usually affect both eyes symmetrically. - This bilateral presentation is a key characteristic distinguishing them from other corneal conditions. *It is caused by inflammation.* - **Corneal dystrophies** are primarily genetic and degenerative, not inflammatory. - While inflammation can cause corneal damage (e.g., keratitis), it is not the underlying cause of dystrophy. *It involves neovascularization.* - **Neovascularization** (growth of new blood vessels) is typically a response to chronic inflammation, hypoxia, or infection in the cornea. - It is generally not a feature of primary corneal dystrophies, which are characterized by abnormal deposits or structural changes within the corneal layers. *It is usually unilateral.* - As inherited genetic conditions, **corneal dystrophies** almost always affect both eyes. - Unilateral involvement would suggest a different etiology, such as trauma, infection, or a localized acquired condition.

Q: What is the most common complication of pars planitis?

Cataract (clouding of the lens). **Cataract (clouding of the lens)** - **Cataract formation** is the most common ocular complication in patients with pars planitis, often due to chronic inflammation or steroid use. - The inflammation can disrupt lens metabolism, leading to **opacification** over time. *Retinal detachment (separation of retina)* - While possible, **retinal detachment** is a less common complication of pars planitis compared to cataract formation. - It can occur in severe cases, often due to vitreous traction on fragile peripheral retina or tears associated with **snowbanking**. *Cystoid macular edema (swelling of central retina)* - **Cystoid macular edema (CME)** is a significant cause of vision loss in pars planitis but is not the most frequent complication overall. - It results from the inflammatory compromise of the blood-retinal barrier, leading to fluid accumulation in the **macula**. *Glaucoma (increased intraocular pressure)* - **Glaucoma** can occur in pars planitis, often secondary to chronic inflammation affecting the **trabecular meshwork** or prolonged steroid use. - However, it is less common than cataracts and CME as a primary complication.

Q: Jack in box scotoma is seen after correction of Aphakia by?

Spectacles. ***Spectacles*** - **Jack-in-the-box scotoma** describes a visual phenomenon where objects appear to jump into and out of the field of vision. This occurs due to the **peripheral scotoma** and **ring scotoma** created by high-plus aphakic spectacle lenses. - Aphakic spectacles cause significant **magnification of the central visual field** (about 25-30%) and a corresponding minification/displacement of the peripheral field, leading to areas where objects are transiently obscured or reappear. *IOL* - An **intraocular lens (IOL)** replaces the natural lens within the eye, providing a much more stable and centered optical correction. - IOLs generally do not cause significant magnification changes or the peripheral scotoma associated with aphakic spectacles. *Contact lens* - **Contact lenses** sit directly on the cornea, offering a visual correction that is much closer to the nodal point of the eye than spectacles. - This placement results in less peripheral distortion and magnification compared to spectacles, making jack-in-the-box scotoma unlikely. *None of the options* - As **aphakic spectacles** are known to cause jack-in-the-box scotoma, this option is incorrect.

Q: Shaffer's sign is seen in ?

Retinal detachment. ***Retinal detachment*** - **Shaffer's sign** refers to the presence of **pigment cells** (tobacco dust) in the **anterior vitreous**, indicating a retinal break or detachment. - This sign is due to the release of retinal pigment epithelium cells into the vitreous following a tear in the retina. *Acute angle-closure glaucoma* - This condition is characterized by a **sudden increase in intraocular pressure** due to blocked fluid outflow, causing pain, redness, and blurred vision. - It does not involve pigment cells in the vitreous, but rather changes in the **anterior chamber angle**. *Diabetic retinopathy* - This is a microvascular complication of diabetes, leading to damage to the blood vessels in the retina, causing **hemorrhages**, **exudates**, and **neovascularization**. - It does not typically present with free pigment in the vitreous as a primary diagnostic sign. *Age-related macular degeneration* - This condition affects the **macula**, often causing distorted vision and central vision loss, and is characterized by drusen and atrophy. - While it can involve retinal changes, it does not classically present with pigment cells in the vitreous as a diagnostic indicator.

Q: Which type of congenital cataract is commonly associated with significant visual defects?

Nuclear cataract. ***Nuclear cataract*** - It involves the **nucleus** of the lens, which is the central and most visually critical part. - This type of cataract can cause **significant visual impairment** due to its central location and density, impacting early visual development. *Punctate Cataract* - These are **small, dot-like opacities** that are usually clinically insignificant and do not typically cause significant visual defects. - They are often **peripheral** or very fine, thus not obstructing the central visual axis. *Blue dot cataract* - Also known as **cerulean cataract**, this type consists of small, bluish opacities in the lens cortex. - While congenital, it often has **minimal impact on vision** and is frequently observed incidentally. *Fusiform cataract* - This cataract forms in the shape of a **spindle or needle**, usually along the visual axis. - While it can sometimes cause minor visual compromise, its impact is generally **less severe** compared to a dense nuclear cataract.

Q: Which of the following is not an alpha-blocker?

Atenolol. ***Atenolol*** - Atenolol is a **selective beta-1 adrenergic receptor blocker**, primarily used to treat hypertension, angina, and certain arrhythmias. - Its mechanism of action involves **blocking the effects of adrenaline** on the heart, leading to decreased heart rate and blood pressure, rather than affecting alpha receptors. *Indoramine* - Indoramine is an **alpha-1 adrenergic receptor blocker** used historically for hypertension. - It specifically **antagonizes alpha-1 receptors** in vascular smooth muscle, causing vasodilation. *Idazoxan* - Idazoxan is an **alpha-2 adrenergic receptor antagonist**, primarily used in research contexts. - It **blocks presynaptic alpha-2 receptors**, which can lead to an increase in norepinephrine release. *Prazosin* - Prazosin is a well-known **alpha-1 adrenergic receptor blocker** used to treat hypertension and benign prostatic hyperplasia (BPH). - It causes **vasodilation** by relaxing vascular smooth muscle, thus lowering blood pressure.

Q: Guanethidine is used in the treatment of which of the following conditions?

Thyrotoxic ophthalmopathy. ***Thyrotoxic ophthalmopathy*** - Guanethidine is an **adrenergic neuron blocker** that can be used topically to reduce the sympathetic overactivity in the eye associated with thyrotoxicosis. - It helps alleviate symptoms like **retraction of the eyelids** and proptosis by blocking norepinephrine release from sympathetic nerve endings. *Ptosis* - **Ptosis** is primarily caused by weakness of the levator palpebrae superioris muscle or oculomotor nerve dysfunction, not sympathetic overactivity. - Guanethidine would not address the underlying muscular or neurologic deficit causing ptosis. *Bell's palsy* - **Bell's palsy** involves sudden, temporary weakness or paralysis of the muscles on one side of the face due to a dysfunction of the facial nerve. - Treatment typically involves corticosteroids and antivirals; guanethidine has no role in its management. *Horner's syndrome* - **Horner's syndrome** is characterized by miosis, ptosis, and anhidrosis, resulting from damage to the sympathetic nerve supply to the eye and face. - Guanethidine's mechanism of action would exacerbate, rather than treat, the existing sympathetic deficit in Horner's syndrome.

Q: What is the primary therapeutic use of 5-HT1B/1D agonists?

Acute migraine treatment. ***Acute migraine treatment*** - 5-HT1B/1D agonists, such as **triptans**, primarily work by causing **vasoconstriction of intracranial blood vessels** and inhibiting the release of pro-inflammatory neuropeptides. - This action directly alleviates the pain and associated symptoms of **acute migraine attacks**. *Anti-anxiety medications* - Anti-anxiety medications typically target neurotransmitter systems like **GABA** (e.g., benzodiazepines) or **serotonin reuptake** (e.g., SSRIs), not the 5-HT1B/1D receptors in this context. - While serotonin plays a role in anxiety, specific 5-HT1B/1D agonism does not lead to anxiolytic effects. *Anti-nausea medications for chemotherapy* - Anti-nausea medications used for chemotherapy-induced nausea and vomiting often target **5-HT3 receptors** (e.g., ondansetron) to block their pro-emetic effects. - 5-HT1B/1D agonists do not have primary anti-emetic properties useful in this setting. *Drugs for gastroesophageal reflux disease (GERD)* - GERD medications primarily focus on reducing stomach acid production (e.g., **proton pump inhibitors**, H2 blockers) or neutralizing it (antacids). - 5-HT1B/1D agonists do not directly influence gastric acid secretion or esophageal motility in a way beneficial for GERD.

Question 1

Which graphical representation is best suited for depicting continuous quantitative data?

Accepted Answer

Histogram

Answer

Bar diagram

Answer

Pie chart

Answer

Pictogram

Question 2

Coxsackie virus is classified as which type of virus?

Accepted Answer

Enterovirus

Answer

Pox virus

Answer

Myxovirus

Answer

Herpes virus

Question 3

Which of the following statements about corneal dystrophy is true?

Accepted Answer

It is typically bilateral.

Answer

It involves neovascularization.

Answer

It is caused by inflammation.

Answer

It is usually unilateral.

Question 4

What is the most common complication of pars planitis?

Accepted Answer

Cataract (clouding of the lens)

Answer

Retinal detachment (separation of retina)

Answer

Cystoid macular edema (swelling of central retina)

Answer

Glaucoma (increased intraocular pressure)

Question 5

Jack in box scotoma is seen after correction of Aphakia by?

Accepted Answer

Spectacles

Answer

IOL

Answer

Contact lens

Answer

None of the options

Question 6

Shaffer's sign is seen in ?

Accepted Answer

Retinal detachment

Answer

Acute angle-closure glaucoma

Answer

Diabetic retinopathy

Answer

Age-related macular degeneration

Question 7

Which type of congenital cataract is commonly associated with significant visual defects?

Accepted Answer

Nuclear cataract

Answer

Punctate Cataract

Answer

Blue dot cataract

Answer

Fusiform cataract

Question 8

Which of the following is not an alpha-blocker?

Accepted Answer

Atenolol

Answer

Indoramine

Answer

Idazoxan

Answer

Prazosin

Question 9

Guanethidine is used in the treatment of which of the following conditions?

Accepted Answer

Thyrotoxic ophthalmopathy

Answer

Ptosis

Answer

Bell's palsy

Answer

Horner's syndrome

Question 10

What is the primary therapeutic use of 5-HT1B/1D agonists?

Accepted Answer

Acute migraine treatment

Answer

Anti-anxiety medications

Answer

Anti-nausea medications for chemotherapy

Answer

Drugs for gastroesophageal reflux disease (GERD)

NEET-PG 2012

Community Medicine

Microbiology

Ophthalmology

Pharmacology