NEET-PG 2012 Practice Questions

Q: According to WHO guidelines, what prevalence of Bitot's spots indicates a public health problem?

≥ 0.5% prevalence. ***≥ 0.5% prevalence*** - According to **WHO guidelines**, a prevalence of Bitot's spots of **≥ 0.5%** (greater than or equal to 0.5%) in children aged 6-71 months indicates a **moderate public health problem** related to **vitamin A deficiency**. - This threshold is used for **programmatic decision-making** and intervention strategies to combat **xerophthalmia** (vitamin A deficiency eye disease). - At **≥ 1.0%** prevalence, it indicates a **severe public health problem**. *> 1% prevalence* - While ≥ 1% prevalence indicates a **severe public health problem**, the **initial WHO threshold** for identifying a public health problem due to **vitamin A deficiency** as indicated by Bitot's spots is **≥ 0.5%**. - This allows for **earlier public health action** before the situation becomes severe. *> 2% prevalence* - A prevalence of 2% implies a **critical vitamin A deficiency situation**, far exceeding the **WHO's diagnostic threshold** for initiating public health interventions. - Interventions would be critically urgent at this level, but the criteria for recognizing a problem are met at **≥ 0.5%**. *None of the options* - This option is incorrect because the **WHO has specific guidelines** for the prevalence of **Bitot's spots** that indicate a public health problem. - The correct threshold of **≥ 0.5%** is provided among the choices, which is the established criterion for a **moderate public health problem**.

Q: What is the osmolarity of the new Oral Rehydration Solution (ORS)?

245. ***245*** - The **new ORS (reduced osmolarity ORS)** has an osmolarity of **245 mOsmol/L**. - This reduced osmolarity formulation has been shown to be more effective in reducing stool output, vomiting, and duration of diarrhea compared to the standard ORS. *270* - While 270 mOsmol/L is closer to the target, it is not the exact osmolarity of the **new ORS formulation**. - The precise osmolarity of the new ORS is specifically designed for optimal water and electrolyte absorption. *290* - The **standard (or traditional) ORS** had an osmolarity of **310 mOsmol/L**, which is higher than 290 mOsmol/L. - An osmolarity of 290 mOsmol/L does not correspond to a recognized standard or new ORS formulation. *310* - The **standard (or traditional) ORS** formulation had an osmolarity of **310 mOsmol/L**. - The move to a new ORS with reduced osmolarity was to improve efficacy and reduce the risk of hypernatremia in some patients.

Q: What is the primary electrolyte found in Oral Rehydration Salts (ORS) at a concentration of 75 mEq/L?

Sodium. ***Sodium*** - The primary electrolyte in **Oral Rehydration Salts (ORS)** is **sodium**, which is crucial for replacing losses due to diarrhea and facilitating water absorption in the intestines [1]. - The standard ORS formulation, recommended by the WHO, contains **75 mEq/L of sodium** to effectively rehydrate individuals with acute watery diarrhea [1]. *Potassium* - While **potassium** is an essential electrolyte found in ORS, its concentration is typically lower than sodium, usually around **20 mEq/L**. - Potassium helps replenish intracellular losses and supports normal cellular function, but it is not the primary electrolyte at the 75 mEq/L concentration. *Glucose* - **Glucose** is a crucial component of ORS, but it is a sugar, not an electrolyte. - Its role is to facilitate the co-transport of **sodium and water** across the intestinal wall, enhancing fluid absorption, but it does not contribute to the electrolyte concentration in mEq/L [1]. *Chloride* - **Chloride** is an electrolyte present in ORS, primarily to balance the charge of **sodium** and prevent hyynatremia. - Its concentration is typically around **65 mEq/L**, making it slightly less concentrated than sodium but still vital for maintaining electrolyte balance.

Q: What percentage of oral cancer cases is attributed to tobacco use?

70% of cases. ***90%*** - Nicotine is a significant contributor to **oral cancer**, with studies indicating it is responsible for about **90%** of cases [1]. - Its carcinogenic effects are amplified when combined with other risk factors such as **tobacco** and **alcohol** use [1]. *40%* - This percentage underestimates nicotine's role in oral cancer development, which is much higher. - Key studies suggest that the impact of nicotine alone is much greater than **40%**, highlighting its pivotal role in carcinogenesis. *60%* - This estimate also falls short, as the consensus in oncology is that nicotine significantly contributes even beyond **60%**. - Oral cancer risk is further elevated when nicotine is consumed in conjunction with other **carcinogens** [1], rather than just being limited to a single contribution. *10%* - This figure drastically underrepresents nicotine's involvement, as it is a major causative agent in oral cancer. - The **10%** suggestion implies minimal risk, contradicting clinical evidence that strongly supports a far greater role for nicotine. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 738-739.

Q: Which of the following statements about trematodes is true?

Two hosts required. ***Two hosts required (Correct)*** - Trematodes typically require at least **two hosts** to complete their life cycle: an intermediate host (usually a **snail**) and a definitive host (a vertebrate). - This complex lifecycle involving multiple hosts is a characteristic feature of **flukes**. - This is a fundamental distinguishing feature that separates trematodes from some other helminths. *Segmented (Incorrect)* - Trematodes (flukes) have **unsegmented, leaf-shaped or cylindrical bodies**, unlike cestodes (tapeworms) which are segmented. - The absence of body segmentation is a key morphological distinction from other helminths. *Anus present (Incorrect)* - Trematodes have an **incomplete digestive system** with a mouth and an esophagus, but **no anus**. - Waste products are expelled back through the **mouth**. - This blind-ending gut is characteristic of the class Trematoda. *Body cavity present (Incorrect)* - Trematodes are **acoelomates**, meaning they lack a true fluid-filled body cavity (coelom). - Their internal organs are embedded in **parenchymatous tissue** filling the space between body wall and organs.

Q: Schistosomiasis is transmitted by?

Snail. ***Snail*** - **Snails** act as the **intermediate host** for all species of Schistosoma, where the parasite undergoes asexual reproduction. - Humans become infected when they come into contact with water contaminated with **cercariae**, which are released from infected snails. *Cyclops* - **Cyclops** (a type of freshwater crustacean) are the intermediate hosts for parasites like **Dracunculus medinensis** (guinea worm) and **Diphyllobothrium latum** (fish tapeworm). - They are not involved in the life cycle or transmission of Schistosoma. *Fish* - Various fish can be intermediate hosts for parasites such as **Clonorchis sinensis** (Chinese liver fluke) or **Diphyllobothrium latum**. - Fish do not play a role in the transmission of schistosomiasis. *Cattle* - **Cattle** can serve as definitive hosts for certain parasites, such as **Taenia saginata** (beef tapeworm), where the larval stage (cysticerci) is found in their muscle tissue. - They are not involved in the life cycle or transmission of Schistosoma.

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: 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: 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.

Question 1

What is the significance of a 2-year post-treatment surveillance period in paucibacillary leprosy?

Accepted Answer

To identify relapses, reactions, and neurological complications after treatment completion

Answer

To monitor for treatment compliance during active therapy

Answer

To assess the effectiveness of multibacillary leprosy treatment protocols

Answer

To detect early signs of drug resistance in ongoing treatment

Question 2

According to WHO guidelines, what prevalence of Bitot's spots indicates a public health problem?

Accepted Answer

≥ 0.5% prevalence

Answer

> 1% prevalence

Answer

> 2% prevalence

Answer

None of the options

Question 3

What is the osmolarity of the new Oral Rehydration Solution (ORS)?

Accepted Answer

245

Answer

270

Answer

290

Answer

310

Question 4

What is the primary electrolyte found in Oral Rehydration Salts (ORS) at a concentration of 75 mEq/L?

Accepted Answer

Sodium

Answer

Potassium

Answer

Glucose

Answer

Chloride

Question 5

What percentage of oral cancer cases is attributed to tobacco use?

Accepted Answer

70% of cases

Answer

60% of cases

Answer

10% of cases

Answer

40% of cases

Question 6

Which of the following statements about trematodes is true?

Accepted Answer

Two hosts required

Answer

Segmented

Answer

Anus present

Answer

Body cavity present

Question 7

Schistosomiasis is transmitted by?

Accepted Answer

Snail

Answer

Fish

Answer

Cattle

Answer

Cyclops

Question 8

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 9

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 10

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.

NEET-PG 2012

Community Medicine

Dental

Microbiology

Ophthalmology