NEET-PG 2013 Practice Questions

Q: What is the unit for a prolactin level of 20 in blood?

ng/ml. ***ng/ml*** - Prolactin levels in blood are typically measured in **nanograms per milliliter (ng/mL)**, reflecting the very small concentrations of hormones. - A value of 20 ng/mL falls within the typical reference range for prolactin. *mg/mL* - **Milligrams per milliliter (mg/mL)** is a unit used for much higher concentrations, more common for drugs or larger molecules, not hormones like prolactin. - If prolactin were measured in mg/mL, a value of 20 mg/mL would be an astronomically high and physiologically impossible level. *mg/L* - **Milligrams per liter (mg/L)** is also a unit for higher concentrations than those typically seen for hormones in blood. - 20 mg/L is equivalent to 20 µg/mL or 20,000 ng/mL, which would indicate severe hyperprolactinemia. *ng/L* - **Nanograms per liter (ng/L)** is a unit for extremely low concentrations. - A reading of 20 ng/L would be too low for normal physiological prolactin levels, as 1 ng/mL equals 1000 ng/L.

Q: Which of the following is the major glycosaminoglycan of synovial fluid?

Hyaluronic acid. ***Hyaluronic acid*** - **Hyaluronic acid** is the primary glycosaminoglycan in **synovial fluid**, providing its characteristic **viscosity** and **lubricating properties**. - It plays a crucial role in maintaining **joint health** by reducing friction and acting as a shock absorber. *Chondroitin sulfate* - **Chondroitin sulfate** is abundant in **cartilage**, contributing to its **compressive strength**. - While present in connective tissues, it is not the major glycosaminoglycan of synovial fluid. *Dermatan sulfate* - **Dermatan sulfate** is primarily found in **skin**, **blood vessels**, and **heart valves**. - Its main roles involve tissue structure and repair, not lubrication of synovial fluid. *Heparan sulfate* - **Heparan sulfate** is found on **cell surfaces** and in the **extracellular matrix**, especially in the **basement membranes**. - It regulates cell growth, adhesion, and signaling, and is not a major component of synovial fluid viscosity.

Q: What is the end product of purine metabolism in humans?

Uric acid. ***Uric acid*** - **Uric acid** is the final breakdown product of **purine metabolism** in humans. - It is formed from the degradation of **adenosine** and **guanosine**, with xanthine oxidase playing a key role in its synthesis. *Allantoin* - **Allantoin** is the end product of **purine metabolism** in most mammals other than primates, as they possess the enzyme **uricase** to further break down uric acid. - Humans lack **uricase**, hence allantoin is not the end product in humans. *Carbon Dioxide* - **Carbon dioxide** is a major end product of **carbohydrate** and **fat metabolism** through cellular respiration. - It is not directly associated with the degradation pathway of purines. *None of the options* - This option is incorrect because **uric acid** is indeed the definitive end product of purine metabolism in humans.

Q: Which of the following statements about HIV associated nephropathy (HIVAN) is incorrect?

HIVAN is associated with shrunken kidneys.. ***Shrunken kidneys*** - In HIV-associated nephropathy, kidneys typically appear **enlarged** due to hyperplasia of podocytes and other glomerular changes. - **Shrunken kidneys** are not a characteristic feature, making this statement incorrect. *Develops when CD4<200* - HIV-associated nephropathy often arises when CD4 counts drop **below 200 cells/mm³**, indicating severe immunosuppression. - This is a common threshold for the occurrence of opportunistic infections and kidney issues in HIV patients. *15% cases show mesengial proliferation* - **Mesangial proliferation** can occur in about **15% to 30%** of cases of HIV-associated nephropathy, which aligns with the typical histological findings. - Incorrect assumptions might stem from misunderstanding the varying morphologies associated with HIV nephropathy. *Proteinuria* - **Proteinuria** is a common clinical feature of HIV-associated nephropathy, with the condition often presenting with significant protein loss in the urine. - The nephropathy especially results in **nephrotic syndrome**, characterized by high levels of proteinuria.

Q: Which of the following is not an obstructive lung disease?

Interstitial fibrosis. ***Interstitial fibrosis*** - **Interstitial fibrosis** is a **restrictive lung disease**, characterized by **reduced lung elasticity** and lung volumes, rather than airway obstruction [1]. - In this condition, the **lung tissue becomes scarred and stiff**, making it difficult to expand fully during inspiration [1]. *Emphysema* - **Emphysema** is a classic **obstructive lung disease** caused by the destruction of the **alveolar walls**, leading to enlarged air spaces and loss of elastic recoil [3]. - This destruction results in **airflow limitation**, particularly during exhalation, as airways collapse prematurely. *Asthma* - **Asthma** is an **obstructive lung disease** characterized by **reversible airway inflammation**, bronchoconstriction, and increased mucus production [2]. - These factors lead to **episodic airflow obstruction**, making it difficult to breathe, especially during exacerbations [2]. *Bronchitis* - **Bronchitis**, particularly **chronic bronchitis**, is an **obstructive lung disease** defined by chronic inflammation of the bronchi. - This inflammation causes **mucus hypersecretion** and narrowing of the airways, leading to persistent cough and airflow limitation.

Q: Hurthle cell carcinoma is a variant of which type of carcinoma?

Follicular carcinoma. **Follicular carcinoma** - **Hürthle cell carcinoma**, also known as **oxyphilic follicular carcinoma**, is a specific variant of **follicular carcinoma of the thyroid**. - It is characterized by the presence of large polygonal cells with abundant eosinophilic, granular cytoplasm known as **Hürthle cells** (or oxyphil cells) within the neoplastic growth. *Medullary carcinoma* - **Medullary carcinoma** originates from the **parafollicular C cells** of the thyroid, which produce calcitonin. - It is histologically distinct, featuring nests or cords of cells often associated with **amyloid deposits**, and is not related to Hürthle cell morphology. *Papillary carcinoma* - **Papillary carcinoma** is the most common type of thyroid cancer, characterized by distinctive **nuclear features** such as **Orphan Annie eye nuclei**, nuclear grooves, and intranuclear cytoplasmic inclusions. - Its histological origin and morphological appearance are different from Hürthle cell neoplasms, which are follicular in origin. *Anaplastic carcinoma* - **Anaplastic carcinoma** is a highly aggressive and undifferentiated thyroid malignancy with a very poor prognosis. - It is characterized by pleomorphic, giant, and spindle cells and lacks the specific differentiation seen in follicular or Hürthle cell tumors.

Q: Gastric carcinoma is associated with all of the following EXCEPT:

Activation of RAS. ***Activation of RAS*** - **RAS mutations** are relatively uncommon in gastric carcinoma compared to other gastrointestinal malignancies. While KRAS mutations can occur in approximately 10-15% of gastric cancers (particularly intestinal type), they are **far less frequent** than in **pancreatic adenocarcinoma** (~90%) or **colorectal carcinoma** (~40%). - In the context of gastric carcinoma, RAS pathway alterations are **not considered a major oncogenic driver** compared to the other molecular changes listed, making this the **LEAST characteristically associated** alteration. *Inactivation of p53* - **Inactivation of the p53 tumor suppressor gene** is one of the most frequent molecular events in gastric carcinoma, occurring in approximately **50-60% of cases**. - Loss of p53 function leads to genomic instability, uncontrolled cell proliferation, and resistance to apoptosis, contributing significantly to **tumorigenesis** and **poor prognosis**. *Over expression of C-met* - **Overexpression of C-MET**, a receptor tyrosine kinase for hepatocyte growth factor (HGF), is commonly observed in gastric carcinoma (30-40% of cases) and is strongly linked to **tumor growth**, **invasion**, and **metastasis**. - C-MET amplification and overexpression promote cell proliferation, survival, migration, and angiogenesis, making it an important **therapeutic target** in advanced gastric cancer. *Over expression of C-erb* - **Overexpression of C-erbB-2 (HER2/neu)** is found in approximately **10-20% of gastric adenocarcinomas**, particularly the intestinal type. - HER2 amplification or overexpression is a significant **prognostic and predictive biomarker**, and is specifically targeted by **trastuzumab** (Herceptin) therapy in HER2-positive advanced gastric cancer, improving survival outcomes.

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

All of the options. ***All of the options*** is correct because each statement is true: **Anti-IgE** - Omalizumab is a **humanized monoclonal antibody** that specifically targets and binds to **free IgE** in the circulation - By binding free IgE, it prevents IgE from attaching to **high-affinity receptors** on mast cells and basophils - This reduces the allergic cascade and prevents release of inflammatory mediators **Given subcutaneously** - Omalizumab is administered via **subcutaneous injection** only - Dosing is typically every **2 to 4 weeks** based on patient's body weight and baseline IgE levels - Not available in oral or intravenous formulations for asthma treatment **Used as add-on therapy in moderate to severe asthma prophylaxis** - FDA approved as **add-on maintenance treatment** for patients aged ≥6 years with **moderate to severe persistent allergic asthma** - Indicated when asthma is **inadequately controlled** with inhaled corticosteroids - Reduces frequency of asthma exacerbations and improves asthma control - Also approved for chronic spontaneous urticaria All three statements accurately describe omalizumab's mechanism, administration route, and clinical indication, making **"All of the options"** the correct answer.

Q: Which of the following is not a cardioselective beta blocker?

Oxprenolol. ***Oxprenolol*** - **Oxprenolol** is a non-selective beta-blocker with **intrinsic sympathomimetic activity (ISA)**, meaning it blocks both β1 and β2 receptors and partially stimulates them. - Its non-selective action means it affects both the heart (β1) and other organs like the lungs (β2), making it less suitable for patients with respiratory conditions. *Nebivolol* - **Nebivolol** is a highly cardioselective beta-blocker that primarily blocks **β1 receptors** and also has **vasodilatory properties** due to nitric oxide release. - Its high selectivity translates to fewer β2-mediated side effects, such as bronchoconstriction. *Atenolol* - **Atenolol** is a **cardioselective beta-blocker** that predominantly blocks **β1 receptors** at therapeutic doses. - This selectivity makes it a common choice for cardiovascular conditions, reducing the risk of bronchospasm compared to non-selective agents. *Betaxolol* - **Betaxolol** is a **cardioselective beta-blocker** primarily used for the treatment of hypertension and glaucoma. - It selectively blocks **β1 adrenergic receptors**, minimizing effects on the lungs compared to non-selective beta-blockers.

Question 1

What is the unit for a prolactin level of 20 in blood?

Accepted Answer

ng/ml

Answer

mg/ml

Answer

mg/l

Answer

ng/l

Question 2

Which of the following is the major glycosaminoglycan of synovial fluid?

Accepted Answer

Hyaluronic acid

Answer

Chondroitin sulfate

Answer

Dermatan sulfate

Answer

Heparan sulfate

Question 3

What is the end product of purine metabolism in humans?

Accepted Answer

Uric acid

Answer

Carbon Dioxide

Answer

Allantoin

Answer

None of the options

Question 4

Which of the following statements about HIV associated nephropathy (HIVAN) is incorrect?

Accepted Answer

HIVAN is associated with shrunken kidneys.

Answer

HIVAN is characterized by proteinuria.

Answer

HIVAN typically develops when CD4 count is less than 200.

Answer

About 15% of cases show mesangial proliferation.

Question 5

Which of the following is not an obstructive lung disease?

Accepted Answer

Interstitial fibrosis

Answer

Emphysema

Answer

Asthma

Answer

Bronchitis

Question 6

Hurthle cell carcinoma is a variant of which type of carcinoma?

Accepted Answer

Follicular carcinoma

Answer

Medullary carcinoma

Answer

Papillary carcinoma

Answer

Anaplastic carcinoma

Question 7

Gastric carcinoma is associated with all of the following EXCEPT:

Accepted Answer

Activation of RAS

Answer

Over expression of C-met

Answer

Inactivation of p53

Answer

Over expression of C-erb

Question 8

Dystrophic calcification is seen in

Accepted Answer

Atheromatous plaque

Answer

Vitamin A intoxication

Answer

Milk alkali syndrome

Answer

Hyperparathyroidism

Question 9

Which of the following statements is true regarding omalizumab?

Accepted Answer

All of the options

Answer

Anti-IgE

Answer

Given subcutaneously

Answer

Used as add-on therapy in moderate to severe asthma prophylaxis

Question 10

Which of the following is not a cardioselective beta blocker?

Accepted Answer

Oxprenolol

Answer

Nebivolol

Answer

Atenolol

Answer

Betaxolol

NEET-PG 2013

Biochemistry

Internal Medicine

Pathology

Pharmacology