NEET-PG 2012 Practice Questions

Q: In pediatric growth assessment, what is the typical relationship observed between height and weight in healthy children?

Positive Correlation. ***Positive Correlation*** - In healthy children, as **height increases**, **weight generally also increases** in a predictable pattern, demonstrating a **positive correlation** between these two variables. - This is a fundamental aspect of normal pediatric growth, where both height and weight increase together as children develop. - The **correlation coefficient** between height and weight in healthy children is typically **strong and positive** (r > 0.7). *Negative Correlation* - A **negative correlation** would imply that as height increases, weight decreases, which contradicts normal growth patterns in healthy children. - This relationship might be observed in certain pathological conditions (e.g., severe malnutrition with stunting) but is not characteristic of normal development. *No Correlation* - Stating **no correlation** would mean that changes in height have no predictable linear relationship with changes in weight, which contradicts well-established growth data. - Height and weight are both key anthropometric indicators that are inherently linked during normal growth. *Inverse Relationship* - An **inverse relationship** is synonymous with a negative correlation, suggesting that as one variable increases, the other decreases. - This is incorrect for normal pediatric growth, where height and weight generally trend upwards together throughout childhood.

Q: Measles vaccination is given at -

9 months. ***9 months*** - The first dose of the **measles vaccine (MMR)** is typically administered at **9 months** of age in many national immunization programs. - This timing is chosen because maternal antibodies, which can interfere with vaccine effectiveness, generally wane by this age. *At birth* - Vaccines given at birth, such as **Hepatitis B** and **BCG**, target diseases with early exposure risks or have efficacy despite maternal antibodies. - Giving measles vaccine at birth would be ineffective due to the presence of **maternal antibodies** that neutralize the vaccine virus. *4 weeks* - This age is generally too early for measles vaccination as significant levels of **maternal antibodies** are often still present, which would reduce the vaccine's efficacy. - Other vaccines, like the rotavirus vaccine, might be given around this age, but not measles. *8 weeks* - While maternal antibodies might be decreasing, 8 weeks of age is still generally considered too early for optimal measles vaccine response. - Many primary vaccine series (e.g., DTaP, IPV, Hib) begin at 6-8 weeks, but measles is usually delayed further for better efficacy and seroconversion rates.

Q: Which of the following statements is true regarding T cell independent antigens?

They primarily activate B-cells.. ***Correct: They primarily activate B-cells*** - T-cell independent antigens are typically **polysaccharides** (TI-2) or **lipopolysaccharides** (TI-1) with repeating epitopes that can directly cross-link B cell receptors (BCRs) - This direct binding and cross-linking provide a strong enough signal to activate B cells and induce **antibody production** (mainly IgM) without the need for T cell help - They induce a rapid but limited immune response with minimal memory formation *Incorrect: They primarily activate T-cells* - T-cell independent antigens do not require processing and presentation by **MHC molecules**, which is essential for T cell activation - T cells recognize processed peptides presented by MHC, a mechanism not utilized by T-cell independent antigens - By definition, these antigens activate B cells **without** T cell involvement *Incorrect: They primarily activate macrophages* - While macrophages are antigen-presenting cells, their primary role in adaptive immunity is to process and present antigens to T cells - Macrophages are involved in **phagocytosis** and antigen processing, but are not the primary target cells for T-independent antigens - The key feature of TI antigens is direct B cell activation, not macrophage activation *Incorrect: They primarily activate CD8+ T cells* - **CD8+ T cells** are activated by processed antigens presented on **MHC class I molecules**, typically derived from intracellular pathogens - T-cell independent antigens do not utilize this pathway and are primarily involved in **humoral immunity** through direct B cell activation - TI antigens cannot activate CD8+ T cells as they bypass the T cell-dependent pathway entirely

Q: Which of the following statements is true regarding Diphyllobothrium?

The operculated egg is a diagnostic feature. ***The operculated egg is a diagnostic feature*** - *Diphyllobothrium latum*, also known as the **fish tapeworm**, produces characteristic **operculated eggs** that are oval-shaped with an operculum (cap) at one end and a small knob at the other. - The presence of these **unembryonated eggs** in stool samples is the primary diagnostic method for diphyllobothriasis. *Humans are the only definitive host* - While humans are common definitive hosts, other **fish-eating mammals** such as bears, dogs, and cats can also serve as definitive hosts for *Diphyllobothrium latum*. - The definitive host is where the **adult worm resides** and reproduces sexually. *Vitamin B12 deficiency always occurs in infection* - **Vitamin B12 deficiency (megaloblastic anemia)** is a known complication of *Diphyllobothrium latum* infection, as the worm competes for B12 in the host's intestine. - However, it does **not occur in all infected individuals**; it is estimated to affect a significant minority, typically those with heavy worm burdens or prolonged infection, and can be influenced by dietary intake. *Fish are definitive hosts* - Fish (specifically freshwater fish like pike, perch, and salmon) act as **second intermediate hosts** for *Diphyllobothrium latum*, carrying the **plerocercoid larvae**. - **Humans and other fish-eating mammals** are the definitive hosts, where the plerocercoid larvae mature into adult tapeworms in the small intestine.

Q: Unsegmented eggs are in which parasite?

Trichuris trichiura. ***Trichuris trichiura*** - *Trichuris trichiura* (whipworm) eggs are typically **unembryonated** or **unsegmented** when passed in feces. - Upon defecation, the eggs require a period of **development in soil** to become infective. *Ancylostoma* - **Hookworm (Ancylostoma)** eggs are typically **segmented** (possessing a 2-8 cell stage) when passed in feces. - They develop into **rhabditiform larvae** in the soil. *Necator americanus* - **Hookworm (Necator americanus)** eggs are also typically **segmented** (possessing a 2-8 cell stage) when passed in feces. - Like *Ancylostoma*, they require further development in soil to become infective. *Dracunculus* - *Dracunculus medinensis* (Guinea worm) does not lay eggs; instead, it releases **larvae** from the skin blister of the host into water. - The larvae are then ingested by **cyclops** (copepods) to continue their life cycle.

Q: In which condition is the swinging light test positive?

Optic neuritis. ***Optic neuritis*** - The swinging light test (also known as the **Marcus Gunn pupil** or relative afferent pupillary defect, RAPD) is positive when there is a significant **asymmetry in the afferent visual pathway** between the two eyes. - In optic neuritis, the **optic nerve** is inflamed and demyelinated, impairing the transmission of light signals to the brain, which leads to a paradoxical pupillary dilation when the light is swung from the unaffected to the affected eye. *Conjunctivitis* - This is an **inflammation of the conjunctiva**, the membrane lining the eyelid and sclera, which primarily affects the ocular surface. - It does not involve the optic nerve or afferent pupillary pathways, so the swinging light test would be **negative**. *Glaucoma* - Glaucoma is a condition characterized by **progressive optic nerve damage**, often associated with elevated intraocular pressure, leading to peripheral vision loss. - While it causes optic neuropathy, a positive swinging light test is typically seen only in **severe, asymmetric cases** and is not its primary diagnostic feature. *Keratoconus* - This is a non-inflammatory eye condition in which the normally round dome-shaped cornea **thins and bulges outward into a cone-like shape**. - It affects the **cornea's shape and vision quality**, but not the optic nerve or the afferent pupillary reflex pathway, thus the swinging light test would be negative.

Q: Which gene mutation is commonly associated with malignant melanoma?

CDKN2A. ***CDK2A*** - CDK2A mutations are implicated in malignant melanoma as they disrupt the **cell cycle regulation**, contributing to uncontrolled cell growth [1]. - Loss of CDK2A function leads to reduced **p16INK4A**, a crucial inhibitor of cyclin-dependent kinases involved in **G1/S phase transition** [1,3]. - Germline mutations of p16 (CDKN2A) are present in 25% of melanoma-prone kindreds [2], and germline mutations in CDKN2A are associated with familial forms of melanoma [3]. *RET* - RET mutations are primarily associated with **medullary thyroid carcinoma** and **multiple endocrine neoplasia type 2**, not melanoma. - It is involved in the signaling pathways but does not have a direct link to melanoma pathogenesis. *None* - Suggesting "none" misrepresents the reality that specific mutations do occur in malignant melanoma, including **CDK2A** and **BRAF**. - This option fails to recognize the importance of genetic alterations in cancer development and progression. *N-myc* - N-myc mutations are primarily associated with **neuroblastoma** and not typically linked to malignant melanoma. - In melanoma, mutations of this gene do not play a significant role in its pathophysiology compared to another tumor suppressor gene like **CDK2A**. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1150-1151. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, pp. 297-298. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, pp. 305-306.

Q: When should breastfeeding be initiated after a normal delivery?

Immediately after delivery. **Correct: Immediately after delivery** - Initiating breastfeeding **within the first hour** of birth (early initiation) is crucial for establishing **successful lactation** and promoting optimal infant health. - This early initiation allows for **skin-to-skin contact**, which helps stabilize the newborn's temperature, heart rate, and breathing, and facilitates **bonding** between mother and baby. - Aligned with **WHO and UNICEF recommendations** for best practice in postpartum care. *Incorrect: 2 hours after delivery* - While earlier is generally better, waiting two hours misses the **optimal window** for initiating feeding and bonding. - The newborn's **alert period** is typically strongest in the first hour post-birth, making it an ideal time for the first latch. *Incorrect: 4 hours after delivery* - Delaying breastfeeding by four hours can make it more challenging for the baby to latch effectively as they may have passed their **initial alert state** and become sleepy. - This delay can also hinder the establishment of the mother's **milk supply**, as stimulation from early feeding is important for prolactin release. *Incorrect: 6 hours after delivery* - Waiting six hours significantly **misses the critical window** for early initiation and can lead to increased difficulties with breastfeeding. - Prolonged delays may necessitate supplementation, potentially interfering with exclusive breastfeeding and establishing a **strong milk supply**.

Q: What is the best drug for open-angle glaucoma?

Latanoprost. Latanoprost - Latanoprost is a prostaglandin analog and is often considered a first-line treatment for open-angle glaucoma due to its efficacy in reducing intraocular pressure (IOP) and its once-daily dosing. - It works by increasing the outflow of aqueous humor through the uveoscleral pathway, thereby lowering IOP. Pilocarpine - Pilocarpine is a cholinergic agonist that causes miosis and ciliary muscle contraction [3], increasing the outflow of aqueous humor through the trabecular meshwork [4]. - While effective, its side effects (e.g., accommodative spasm, miosis) [1] and more frequent dosing make it generally a second-line or third-line agent for long-term management compared to prostaglandins. Physostigmine - Physostigmine is an acetylcholinesterase inhibitor that indirectly increases acetylcholine, mimicking cholinergic stimulation. - Although it can lower IOP, it is generally not used for open-angle glaucoma due to significant side effects and the availability of safer, more effective alternatives [1]. Apraclonidine - Apraclonidine is an alpha-2 adrenergic agonist [2] used primarily for short-term control of IOP, especially before or after ocular surgery, or as an adjunct therapy. - Its efficacy as a long-term monotherapy for open-angle glaucoma is limited by tachyphylaxis and potential for significant systemic side effects with chronic use.

Q: What is the recommended thickness of lead apron to prevent radiation exposure?

0.5 mm. ***0.5 mm*** - A **0.5 mm lead equivalent apron** is the universally accepted standard for protecting against primary beam radiation in most medical imaging procedures, including fluoroscopy and interventional radiology. - This thickness provides adequate **radiation attenuation** to significantly reduce dose to the wearer while maintaining reasonable comfort and mobility. *1 mm* - While offering increased attenuation, a **1 mm lead equivalent apron** is considerably heavier and less practical for routine use, leading to greater physical strain without a proportional increase in necessary protection for most procedures. - The additional weight and bulk can hinder movement and reduce compliance, especially during long procedures. *3 mm* - A **3 mm lead equivalent apron** would be excessively heavy and restrictive for medical personnel, making it highly impractical for general use in radiology departments. - The degree of protection offered by such an apron far exceeds the requirements for standard diagnostic and interventional procedures, incurring unnecessary physical burden. *7 mm* - A **7 mm lead equivalent apron** is an extreme thickness that would be entirely unfeasible for an individual to wear due to its immense weight and stiffness. - This level of shielding is typically found in fixed architectural barriers for radiation protection, such as walls of an X-ray room, not in personal protective equipment.

Question 1

In pediatric growth assessment, what is the typical relationship observed between height and weight in healthy children?

Accepted Answer

Positive Correlation

Answer

Negative Correlation

Answer

No Correlation

Answer

Inverse Relationship

Question 2

Measles vaccination is given at -

Accepted Answer

9 months

Answer

At birth

Answer

4 weeks

Answer

8 weeks

Question 3

Which of the following statements is true regarding T cell independent antigens?

Accepted Answer

They primarily activate B-cells.

Answer

They primarily activate T-cells.

Answer

They primarily activate macrophages.

Answer

They primarily activate CD8+ T cells.

Question 4

Which of the following statements is true regarding Diphyllobothrium?

Accepted Answer

The operculated egg is a diagnostic feature

Answer

Humans are the only definitive host

Answer

Vitamin B12 deficiency always occurs in infection

Answer

Fish are definitive hosts

Question 5

Unsegmented eggs are in which parasite?

Accepted Answer

Trichuris trichiura

Answer

Ancylostoma

Answer

Necator americanus

Answer

Dracunculus

Question 6

In which condition is the swinging light test positive?

Accepted Answer

Optic neuritis

Answer

Conjunctivitis

Answer

Glaucoma

Answer

Keratoconus

Question 7

Which gene mutation is commonly associated with malignant melanoma?

Accepted Answer

CDKN2A

Answer

MYCN

Answer

RET

Answer

BRAF

Question 8

When should breastfeeding be initiated after a normal delivery?

Accepted Answer

Immediately after delivery

Answer

2 hours after delivery

Answer

4 hours after delivery

Answer

6 hours after delivery

Question 9

What is the best drug for open-angle glaucoma?

Accepted Answer

Latanoprost

Answer

Pilocarpine

Answer

Physostigmine

Answer

Apraclonidine

Question 10

What is the recommended thickness of lead apron to prevent radiation exposure?

Accepted Answer

0.5 mm

Answer

1 mm

Answer

3 mm

Answer

7 mm

NEET-PG 2012

Community Medicine

Microbiology

Ophthalmology

Pathology

Pediatrics

Pharmacology

Radiology