NEET-PG 2013 Practice Questions

Q: Clinical effect of vitamin D is reduced by ?

Simultaneous ingestion of phytates. ***Simultaneous ingestion of phytates*** - **Phytates (phytic acid)** found in whole grains, nuts, seeds, and legumes can **reduce the clinical effect of vitamin D** through multiple mechanisms - Phytates **chelate calcium** and form insoluble calcium-phytate complexes, reducing calcium absorption - Since **vitamin D and calcium metabolism are closely linked**, impaired calcium absorption indirectly reduces vitamin D efficacy - Phytates can also **directly bind to vitamin D** in the gastrointestinal tract, reducing its bioavailability - Studies show that **high phytate intake increases vitamin D requirements** and can impair vitamin D status *Simultaneous ingestion of lactose* - Lactose does **not reduce** vitamin D absorption or efficacy - In fact, **dairy products are commonly fortified** with vitamin D, and the presence of lactose does not interfere with its beneficial effects - Lactose may actually **enhance calcium absorption**, which works synergistically with vitamin D *Acidic environment* - Vitamin D is a **fat-soluble vitamin** absorbed primarily in the small intestine - An acidic environment (stomach acid) is **not known to inhibit** vitamin D absorption - The absorption process occurs in the **alkaline environment of the small intestine** where fat-soluble vitamins are absorbed with dietary fats *None of the options* - This is **incorrect** as phytates do reduce the clinical effect of vitamin D through calcium chelation and direct binding mechanisms

Q: Which of the following vaccines is not typically given in disaster situations?

Influenza. ***Influenza*** - **Influenza vaccination** is generally **NOT a priority** in acute disaster response and emergency vaccination campaigns. - While influenza can spread in crowded conditions, routine disaster response protocols focus on **immediately life-threatening and epidemic-prone diseases** rather than seasonal respiratory infections. - Influenza vaccination requires **cold chain maintenance** and repeated doses, making it logistically challenging in emergency settings. - WHO and SPHERE guidelines do not list influenza among priority vaccines for disaster situations unless there is a specific ongoing outbreak. *Cholera* - **Oral cholera vaccine (OCV)** is increasingly recommended by WHO for disaster settings with **high cholera risk**, particularly in areas with poor water and sanitation. - Modern OCVs (like Shanchol and Euvichol) have improved **cost-effectiveness** and logistics, making them viable for mass campaigns. - Used in conjunction with **WASH interventions** (water, sanitation, hygiene) for comprehensive cholera control. *Measles* - **Measles vaccination** is the **highest priority** vaccine in disaster response, particularly for children aged 6 months to 15 years. - Its **extreme contagiousness** (R0 = 12-18) and high mortality in malnourished populations make it critical. - WHO recommends measles vaccination within the **first days** of a disaster response in displacement settings. *Tetanus* - **Tetanus toxoid** (often as Td or DT) is essential in disasters involving injuries, floods, earthquakes, or debris. - Protects against **_Clostridium tetani_** infection from contaminated wounds. - Part of standard **wound management protocols** in emergency medical care.

Q: The population is divided into homogeneous subgroups, and then individuals are randomly selected from each subgroup. What type of sampling is this?

Stratified random. ***Stratified random*** - In **stratified random sampling**, the population is first divided into homogeneous subgroups (strata), and then a simple random sample is drawn from each stratum. - This method ensures representation from all subgroups, which is implied by the description "separated into groups, from each group people are selected randomly." *Simple random* - **Simple random sampling** involves selecting individuals from an entire population purely by chance, where each individual has an equal probability of being chosen. - This method does not involve an initial division of the population into distinct groups before selection. *Systematic random* - **Systematic random sampling** involves selecting every nth individual from a list after a random starting point. - This method does not involve dividing the population into groups and then sampling from each group. *Cluster* - **Cluster sampling** involves dividing the population into clusters (usually naturally occurring groups), randomly selecting a few clusters, and then sampling *all* individuals within the selected clusters. - In cluster sampling, individuals are not randomly selected *from each* group; instead, entire groups are selected.

Q: What is the most common cause of ASOM?

Pneumococci. ***Pneumococci*** - **_Streptococcus pneumoniae_ (Pneumococci)** is the **most common bacterial cause** of Acute Suppurative Otitis Media (ASOM) in all age groups, particularly in young children. - It accounts for an estimated 25-50% of all ASOM cases, often leading to significant inflammation and **purulent discharge**. *Meningococci* - **_Neisseria meningitidis_ (Meningococci)** is rarely a cause of ASOM. - It is primarily known for causing **meningitis** and **sepsis**, not typically middle ear infections. *H. influenzae* - **_Haemophilus influenzae_ (non-typable)** is the **second most common cause** of ASOM, accounting for 20-40% of cases. - While significant, it is generally less prevalent than _Streptococcus pneumoniae_. *Moraxella catarrhalis* - **_Moraxella catarrhalis_** is another common causative agent of ASOM, responsible for 10-20% of cases. - It is frequently seen in conjunction with other pathogens but is not the most common on its own.

Q: Cone of light focuses on which quadrant of tympanic membrane?

Anteroinferior. ***Anteroinferior*** - The **cone of light** (or light reflex) is a characteristic triangular reflection of the otoscope's light, normally visible in the **anteroinferior quadrant** of a healthy tympanic membrane. - Its presence indicates a **healthy, intact eardrum** with normal tension and transparency; its absence or distortion can suggest pathology. *Posteroinferior* - While part of the tympanic membrane, the **posteroinferior quadrant** does not normally exhibit the focused cone of light. - This area is more often associated with the **round window niche** on its medial aspect in relation to the middle ear. *Anterosuperior* - The **anterosuperior quadrant** is located above the handle of the malleus and does not show the cone of light reflection. - This area contains the **anterior malleolar fold** and part of the **pars flaccida** (attic region). *Posterosuperior* - The **posterosuperior quadrant** is also not the usual site for the cone of light. - This area is relevant for the proximity to the **facial nerve** and structures like the **long process of the incus**.

Q: What does testamentary capacity refer to?

Ability to make a valid will. ***Ability to make a valid will*** - **Testamentary capacity** specifically refers to the legal and mental competence required to create a legally binding **last will and testament**. - It ensures that the testator understands the nature of the act, the extent of their property, and the natural objects of their bounty (i.e., those who would reasonably expect to inherit). *Ability to create a will* - While related, this option is too broad; it doesn't emphasize the **legal validity** or the specific cognitive requirements involved in the process. - Simply "creating" a will may involve just writing it down, but it doesn't guarantee the **mental capacity** needed for it to be enforceable. *Ability to understand legal documents* - This is a general cognitive ability that is necessary but insufficient to define **testamentary capacity**. - A person might understand legal documents generally but lack the specific awareness of their assets or beneficiaries required for a valid will at a given time. *None of the options* - This is incorrect because the first option accurately describes **testamentary capacity**.

Q: Which of the following bacteria is known to exhibit antigenic variation?

Borrelia. ***Borrelia*** - *Borrelia* species, particularly *Borrelia burgdorferi* (causing **Lyme disease**), are known for extensive **antigenic variation** of their outer surface proteins (Osps), especially OspC. - This variation helps the bacteria evade the host's immune response, contributing to persistent infection. *Yersinia* - While *Yersinia* species produce various virulence factors, including proteins that interfere with immune cell function, they are not primarily known for the type of rapid and extensive **antigenic variation**seen in *Borrelia*. - Their immune evasion strategies often involve modifying host cell signaling pathways and resisting phagocytosis. *Bordetella* - *Bordetella pertussis*, causative agent of **whooping cough**, varies its expression of adhesins and toxins through **phase variation**, which is a form of phenotypic switching. - However, this is distinct from the frequent and sequential changes in surface antigens (antigenic variation) observed in *Borrelia*. *Brucella* - *Brucella* species are **intracellular pathogens** that primarily evade the immune system by surviving and replicating within host cells. - They do not typically engage in significant **antigenic variation** of their surface components as a primary immune evasion mechanism.

Q: Which of the following is a benzylisoquinoline muscle relaxant?

Doxacurium. ***Doxacurium*** - **Doxacurium** is a long-acting, non-depolarizing neuromuscular blocker classified as a **benzylisoquinoline** compound [1]. - These agents are known for their minimal cardiovascular effects and lack of histamine release in therapeutic doses [1]. *Vecuronium* - **Vecuronium** is an **aminosteroid** non-depolarizing neuromuscular blocker [2]. - It is known for its intermediate duration of action and minimal cardiovascular effects [1]. *Rocuronium* - **Rocuronium** is also an **aminosteroid** non-depolarizing neuromuscular blocker [2]. - It has a rapid onset of action, making it suitable for rapid sequence intubation, and can be reversed by **sugammadex**. *Pancuronium* - **Pancuronium** is an **aminosteroid** non-depolarizing neuromuscular blocker with a long duration of action [1]. - It is associated with a vagolytic effect that can cause an increase in **heart rate** and **blood pressure** [1].

Q: Which of the following anticoagulants is given orally?

Rivaroxaban. ***Rivaroxaban*** - Rivaroxaban is a **direct oral anticoagulant (DOAC)** that specifically inhibits **Factor Xa**. - It is administered orally and does not require routine coagulation monitoring. *Argatraban* - Argatroban is a **direct thrombin inhibitor (DTI)** primarily used intravenously, especially in patients with **heparin-induced thrombocytopenia (HIT)**. - It is not an orally administered anticoagulant. *Alteplase* - Alteplase is a **thrombolytic agent** (clot buster), not an anticoagulant, that works by converting **plasminogen to plasmin**. - It is administered intravenously to dissolve existing clots. *Fondaparinux* - Fondaparinux is a **synthetic pentasaccharide** that selectively inhibits **Factor Xa** by binding to antithrombin. - It is administered **subcutaneously**, not orally.

Q: What is the mechanism of action of Warfarin?

Inhibition of Vitamin K epoxide reductase. ***Inhibition of Vitamin K epoxide reductase*** - Warfarin blocks **Vitamin K epoxide reductase (VKORC1)** [1, 2, 3], an enzyme essential for recycling oxidized vitamin K into its active reduced form [1, 3]. - This reduction prevents the activation of **vitamin K-dependent clotting factors** (II, VII, IX, X), leading to anticoagulation [1, 3]. *Inhibition of gamma glutamyl carboxylase* - **Gamma-glutamyl carboxylase** uses reduced vitamin K as a cofactor to carboxylate specific glutamic acid residues on clotting factors [1, 3]. - While essential for clotting factor activation, this enzyme itself is **not directly inhibited by warfarin** [1, 3]. *Activation of Vitamin K epoxide reductase* - Activating **VKORC1** would increase the production of reduced vitamin K, thereby **promoting coagulation** rather than inhibiting it [1, 2]. - This is the opposite of warfarin's intended therapeutic effect. *Activation of gamma glutamyl carboxylase* - Activating **gamma-glutamyl carboxylase** would enhance the carboxylation and activation of **clotting factors**, leading to procoagulant effects [1, 3]. - This mechanism contradicts warfarin's role as an **anticoagulant**.

Question 1

Clinical effect of vitamin D is reduced by ?

Accepted Answer

Simultaneous ingestion of phytates

Answer

Simultaneous ingestion of lactose

Answer

None of the options

Answer

Acidic environment

Question 2

Which of the following vaccines is not typically given in disaster situations?

Accepted Answer

Influenza

Answer

Measles

Answer

Cholera

Answer

Tetanus

Question 3

The population is divided into homogeneous subgroups, and then individuals are randomly selected from each subgroup. What type of sampling is this?

Accepted Answer

Stratified random

Answer

Simple random

Answer

Cluster

Answer

Systematic random

Question 4

What is the most common cause of ASOM?

Accepted Answer

Pneumococci

Answer

Meningococci

Answer

H. influenzae

Answer

Moraxella catarrhalis

Question 5

Cone of light focuses on which quadrant of tympanic membrane?

Accepted Answer

Anteroinferior

Answer

Posteroinferior

Answer

Anterosuperior

Answer

Posterosuperior

Question 6

What does testamentary capacity refer to?

Accepted Answer

Ability to make a valid will

Answer

None of the options

Answer

Ability to create a will

Answer

Ability to understand legal documents

Question 7

Which of the following bacteria is known to exhibit antigenic variation?

Accepted Answer

Borrelia

Answer

Yersinia

Answer

Bordetella

Answer

Brucella

Question 8

Which of the following is a benzylisoquinoline muscle relaxant?

Accepted Answer

Doxacurium

Answer

Rocuronium

Answer

Pancuronium

Answer

Vecuronium

Question 9

Which of the following anticoagulants is given orally?

Accepted Answer

Rivaroxaban

Answer

Argatraban

Answer

Alteplase

Answer

Fondaparinux

Question 10

What is the mechanism of action of Warfarin?

Accepted Answer

Inhibition of Vitamin K epoxide reductase

Answer

Inhibition of gamma glutamyl carboxylase

Answer

Activation of Vitamin K epoxide reductase

Answer

Activation of gamma glutamyl carboxylase

NEET-PG 2013

Biochemistry

Community Medicine

ENT

Forensic Medicine

Microbiology

Pharmacology