NEET-PG 2020 Practice Questions

Q: Which of the following is true about non-competitive inhibition?

Km remains same, Vmax decreases. ***Km remains same, Vmax decreases*** - In **non-competitive inhibition**, the inhibitor binds to an allosteric site on the enzyme, altering its conformation, thereby **reducing its catalytic efficiency**. - This binding does not affect the **enzyme's affinity for the substrate (Km remains the same)**, but it **reduces the maximum reaction rate (Vmax decreases)** because fewer enzyme molecules are able to perform catalysis per unit time. *Km increases, Vmax remains same* - This describes **competitive inhibition**, where the inhibitor competes with the substrate for the enzyme's active site. - While it **increases the apparent Km** (more substrate needed to reach half Vmax), **Vmax remains unchanged** as high substrate concentrations can overcome the inhibition. *Km decreases, Vmax increases* - This scenario would imply an activation rather than inhibition, where both enzyme affinity and catalytic efficiency are enhanced. - This is not characteristic of any standard **enzyme inhibition mechanism**. *Km increases, Vmax increases* - This combination is not observed in any typical **enzyme inhibition pattern**. - An increase in **Vmax** implies enhanced catalytic activity, while an increase in **Km** suggests reduced substrate affinity, which are contradictory effects for a single inhibitor.

Q: Blood bag is discarded in:

Yellow bag. ***Yellow bag*** - The **yellow bag** is designated for **infectious waste** including human anatomical waste, soiled waste, expired medicines, and **items contaminated with blood and body fluids**. - **Blood bags** are disposed in yellow bags as they contain blood and body fluids, making them **infectious/biohazardous waste**. - According to Biomedical Waste Management Rules, items contaminated with blood fall under Category 1 (Yellow bag) waste. - This ensures safe handling and disposal of potentially infectious materials to prevent pathogen transmission. *Red bag* - The red bag is used for **contaminated recyclable plastic waste** such as tubing, IV sets without fluids, catheters, and plastic bottles. - While blood bags are plastic, their **biohazardous content (blood)** classifies them as infectious waste rather than recyclable contaminated plastic. - Red bag items undergo recycling after disinfection, which is not appropriate for blood-contaminated items. *White bag* - A **white/translucent bag** is used for **sharp waste** including needles, syringes with fixed needles, scalpels, and blades. - Blood bags are not sharp objects and do not pose puncture risk, hence not disposed in white bags. *Blue bag* - The **blue bag** is used for **glassware waste** including broken/unbroken contaminated glass vials and ampoules. - Blood bags are made of plastic, not glass, and their primary hazard is infectious content, not material type.

Q: Surgical gloves are disposed in which BMW category ?

Yellow Category (Infectious Waste). ***Yellow Category (Infectious Waste)*** - Surgical gloves are classified as **infectious waste** because they come into contact with blood, body fluids, and other potentially infectious materials during surgical procedures. - The Yellow Category in Bio-Medical Waste Management (BMW) Rules is designated for infectious waste, including items contaminated with **blood and body fluids**. - This is the correct disposal category for used surgical gloves. *Solid Waste* - This is a broad category for general waste that is not infectious or hazardous. - Surgical gloves, due to their potential contamination with infectious materials, are classified more specifically as biomedical waste under the Yellow category, not general solid waste. *Expired or Discarded Medicines* - This category is for pharmaceutical waste, including unused or expired medications. - Surgical gloves are medical devices used for protection, not medicinal products, and therefore do not belong in this category. *Human Anatomical Waste* - This category includes human tissues, organs, body parts, and recognizable anatomical specimens. - Surgical gloves are protective barriers used during procedures, not anatomical waste from the patient, and are classified separately as infectious waste.

Q: A person was brought to emergency department and was diagnosed with Supra ventricular tachycardia and suddenly he became unstable. What is the next line of management?

DC Cardioversion. ***DC Cardioversion*** - For **unstable supraventricular tachycardia (SVT)**, immediate **direct current (DC) cardioversion** is the definitive treatment to restore sinus rhythm. - Instability in SVT includes symptoms like hypotension, altered mental status, signs of shock, ischemic chest discomfort, or acute heart failure. *Intravenous ibutilide* - **Ibutilide** is an antiarrhythmic drug used for pharmacological cardioversion of recent-onset atrial fibrillation or flutter, but not typically for unstable SVT. - While it can convert certain supraventricular arrhythmias, it is generally reserved for **stable patients** and takes longer to act than immediate electrical cardioversion. *Intravenous Diltiazem* - **Diltiazem** is a calcium channel blocker used to control ventricular rate in **stable SVT**, atrial fibrillation, or flutter [1]. - It is contraindicated in unstable patients as it can further depress cardiac contractility and worsen hypotension [2]. *Intravenous Flecainide* - **Flecainide** is a class Ic antiarrhythmic drug used to maintain sinus rhythm in patients with supraventricular arrhythmias, including SVT. - It also takes time to act and is used in **stable patients** without structural heart disease, not in emergency unstable situations where immediate rhythm conversion is required.

Q: A lesion was seen on the face of a 42 year old patient as shown below. Which of the following would be ideal management for this condition?

Start on ATT. ***Start on ATT*** - The presented image shows a **gummy lesion** on the face, which is characteristic of **tuberculosis cutis colliquativa**, a form of cutaneous tuberculosis. - **Anti-tubercular therapy (ATT)** is the primary and most effective treatment for all forms of tuberculosis, including cutaneous manifestations. *Topical retinoids* - Topical retinoids are primarily used for **acne vulgaris** and certain **disorders of keratinization** and are not indicated for infectious granulomatous conditions. - They work by **regulating cell growth and differentiation**, which is not the mechanism required to treat tuberculosis. *Oral steroids* - Oral steroids are **immunosuppressive** and generally contraindicated in active infections like tuberculosis, as they can worsen the disease. - While they might be used short-term in some inflammatory skin conditions, they would **not address the underlying tuberculous infection**. *Start on MDT for leprosy* - **Multi-drug therapy (MDT)** is the standard treatment for leprosy, which also presents with skin lesions and nerve involvement. - However, the image shows a **single, nodular, ulcerated lesion** more typical of cutaneous tuberculosis rather than the varied forms of leprosy (macular, papular, nodular lesions, or nerve thickening).

Q: On esophageal manometry, spastic contractions in the esophageal body with a distal contractile integral (DCI) >8000 mmHg*s*cm are diagnostic of:

Type III achalasia. ***Type III achalasia*** - This diagnosis is characterized by the presence of **spastic contractions** in the esophageal body, specifically with a **distal contractile integral (DCI) greater than 8000 mmHg*s*cm**, alongside the classic features of achalasia (impaired LES relaxation and absent peristalsis) [1]. - The elevated DCI reflects the **premature and simultaneous contractions** that are hallmark of this subtype, distinguishing it from other motility disorders [1]. *Jackhammer esophagus* - While it also involves very strong esophageal contractions (**high DCI**), jackhammer esophagus (also known as hypercontractile esophagus) does **not present with impaired LES relaxation or absent peristalsis** as seen in achalasia. - The defining feature of jackhammer esophagus is **multiple rapid swallows** (MRS) that induce simultaneous contractions, often with very high vigor. *Type II achalasia* - This type of achalasia is defined by **pan-esophageal pressurization** in more than 20% of swallows, along with impaired LES relaxation and absent peristalsis. - Unlike Type III, it does **not show the spastic hypercontractile activity** in the esophageal body revealed by a very high DCI. *Type I achalasia* - This is the classic form of achalasia characterized by **absent esophageal peristalsis** and **impaired lower esophageal sphincter (LES) relaxation**, without significant esophageal pressurization or spastic contractions [1]. - It represents the most common subtype and lacks the **high DCI spastic activity** seen in Type III achalasia.

Q: Which is not seen in heart failure?

Oligemia. ***Oligemia*** - **Oligemia** refers to a reduced blood volume or total blood flow to a region, which is typically not observed in **heart failure**. - In **heart failure**, the body often experiences **fluid overload** and **pulmonary congestion**, leading to increased blood volume in the lungs, not reduced [1]. *Cardiomegaly* - **Cardiomegaly**, or an enlarged heart, is a common finding in **heart failure** as the heart muscle remodels and dilates to compensate for impaired pumping function [1], [3]. - This can be seen on a chest X-ray as an **increased cardiothoracic ratio** [1], [2]. *Kerley B lines* - **Kerley B lines** are thin, horizontal lines visible on a chest X-ray, typically found at the lung periphery. - They indicate **interstitial edema** due to increased pulmonary venous pressure, a characteristic sign of **pulmonary congestion** in **heart failure** [1]. *Kerley A Lines* - **Kerley A lines** are longer, less common lines seen radiating from the hila towards the upper lobes. - These lines represent **distended anastomotic channels** between pulmonary and systemic venous systems, also indicative of **pulmonary edema** and **heart failure** [1], [4].

Q: The shifting fluid sign is characteristic of which condition?

Exudative retinal detachment. ***Exudative retinal detachment (fluid accumulation in subretinal space)*** - The **shifting fluid sign** is pathognomonic for **exudative retinal detachment**, as the subretinal fluid can move with changes in head position due to gravity. - This type of detachment is caused by conditions that lead to abnormal accumulation of fluid under the retina, such as **choroidal tumors**, inflammatory processes, or **severe hypertension**. *Retinal hole (localized retinal break)* - A **retinal hole** is a full-thickness defect in the retina, but it does not inherently cause a shifting fluid sign unless it progresses to a rhegmatogenous detachment. - While it can be a precursor to retinal detachment, the fluid itself is not subject to gravitational shifting in the same way as in exudative detachment. *Tractional retinal detachment (retinal pulling forces)* - **Tractional retinal detachments** occur when **fibrovascular membranes** on the retinal surface contract, pulling the retina away from the underlying choroid. - The detachment is usually localized and fixed by the tractional forces, meaning the fluid (if present) does not shift freely with changes in head position. *Rhegmatogenous retinal detachment (retinal break with vitreous fluid entry)* - This type of detachment involves a **retinal break** through which **liquefied vitreous** gains access to the subretinal space. - Although there is subretinal fluid, the fluid is generally trapped and the detachment is less mobile than in an exudative case; thus, a pronounced shifting fluid sign is not typical.

Q: Which of the following is not a prokinetic?

Loperamide derivative. **Loperamide derivative** - **Loperamide** is an **opioid receptor agonist** that acts on the mu-opioid receptors in the gut, primarily to **decrease gastrointestinal motility** and treat diarrhea. - Its mechanism of action directly opposes that of prokinetic agents, which aim to increase GI motility. *Macrolides* - Certain macrolide antibiotics, particularly **erythromycin**, act as **motilin receptor agonists** at low doses. - This agonism leads to increased gastric motility and can be used as a prokinetic in conditions like gastroparesis. *D2 blocker* - **Dopamine D2 receptor antagonists** (e.g., **metoclopramide**, **domperidone**) block the inhibitory effect of dopamine on cholinergic smooth muscle. - This blockade enhances acetylcholine release, leading to increased gastrointestinal motility and prokinetic effects. *5HT4 agonist* - **Serotonin 5-HT4 receptor agonists** (e.g., **cisapride**, **prucalopride**) stimulate the release of acetylcholine and other excitatory neurotransmitters in the enteric nervous system. - This action promotes increased gastrointestinal motility, making them effective prokinetic agents.

Question 1

Which of the following is true about non-competitive inhibition?

Accepted Answer

Km remains same, Vmax decreases

Answer

Km increases, Vmax remains same

Answer

Km decreases, Vmax increases

Answer

Km increases, Vmax increases

Question 2

Blood bag is discarded in:

Accepted Answer

Yellow bag

Answer

Red bag

Answer

White bag

Answer

Blue bag

Question 3

Surgical gloves are disposed in which BMW category ?

Accepted Answer

Yellow Category (Infectious Waste)

Answer

Solid Waste

Answer

Expired or Discarded Medicines

Answer

Human Anatomical Waste

Question 4

A person was brought to emergency department and was diagnosed with Supra ventricular tachycardia and suddenly he became unstable. What is the next line of management?

Accepted Answer

DC Cardioversion

Answer

Intravenous ibutilide

Answer

Intravenous Diltiazem

Answer

Intravenous Flecainide

Question 5

A lesion was seen on the face of a 42 year old patient as shown below. Which of the following would be ideal management for this condition?

Accepted Answer

Start on ATT

Answer

Topical retinoids

Answer

Oral steroids

Answer

Start on MDT for leprosy

Question 6

On esophageal manometry, spastic contractions in the esophageal body with a distal contractile integral (DCI) >8000 mmHg*s*cm are diagnostic of:

Accepted Answer

Type III achalasia

Answer

Jackhammer esophagus

Answer

Type II achalasia

Answer

Type I achalasia

Question 7

Which is not seen in heart failure?

Accepted Answer

Oligemia

Answer

Cardiomegaly

Answer

Kerley B lines

Answer

Kerley A Lines

Question 8

The shifting fluid sign is characteristic of which condition?

Accepted Answer

Exudative retinal detachment

Answer

Retinal hole

Answer

Tractional retinal detachment

Answer

Rhegmatogenous retinal detachment

Question 9

Which of the following is not a prokinetic?

Accepted Answer

Loperamide derivative

Answer

Macrolides

Answer

D2 blocker

Answer

5HT4 agonist

Question 10

A 55 year old woman diagnosed with ca cervix stage IIb is advised for chemoradiation. Which of the following is the true statement regarding radiation use?

Accepted Answer

Dose/Intensity of radiation is inversely proportional to the square of distance of source

Answer

Rapidly proliferating cells are less affected by radiation

Answer

The small bowel is not significantly affected by radiation

Answer

Small blood vessels are unaffected by radiation

NEET-PG 2020

Biochemistry

Community Medicine

Internal Medicine

Ophthalmology

Pharmacology

Radiology