NEET-PG 2012 Practice Questions

Q: Which is the main vector of Dengue?

A. aegypti. ***A. aegypti*** - **Aedes aegypti** is the primary vector responsible for transmitting the **Dengue virus** to humans. - It is a **day-biting mosquito** found predominantly in tropical and subtropical regions. *Culex* - **Culex mosquitoes** are known vectors for diseases like **Japanese encephalitis**, **West Nile virus**, and **filariasis**. - They are generally **night-biting** and do not play a significant role in Dengue transmission. *Anopheles* - **Anopheles mosquitoes** are the primary vectors for **malaria** in humans. - They are not associated with the transmission of the Dengue virus. *Aedes scutellaris* - While part of the **Aedes genus**, **Aedes scutellaris** is a secondary vector for Dengue in the **Pacific region**. - The main vector for Dengue globally remains **Aedes aegypti**, followed by **Aedes albopictus** in some regions.

Q: All of the following are characteristics of case control study except:

Measures incidence rate. ***Correct: Measures incidence rate*** - A **case-control study** proceeds from effect (disease) to cause (exposure) and thus does **NOT measure the incidence rate** of a disease. - Case-control studies calculate **odds ratios**, not incidence rates. - **Incidence rate** is typically measured in **cohort studies**, where a group of individuals is followed over time to observe the development of new cases of a disease. *Incorrect: Quick results are obtained* - Case-control studies are generally **retrospective**, meaning they look back in time from the outcome (disease) to identify past exposures. - This design allows for **quicker data collection** and analysis compared to prospective studies like cohort studies, which follow individuals over time. - This IS a characteristic of case-control studies. *Incorrect: Proceeds from effect to cause* - In a case-control study, researchers start by identifying individuals with the **disease (cases)** and a comparable group without the disease (controls). - They then investigate past exposures in both groups to determine potential **risk factors** or causes. - This IS a characteristic of case-control studies. *Incorrect: Inexpensive study* - Case-control studies are typically **less expensive** than other analytical study designs, such as cohort studies. - This is because they do not require long-term follow-up of a large population, reducing costs associated with repeated measurements and participant retention. - This IS a characteristic of case-control studies.

Q: What is the estimated time for a dead body to float in water under typical summer conditions in India, considering various influencing factors?

24 hours. ***Correct Answer: 24 hours*** - Under typical summer conditions in India, decomposition is **accelerated due to higher water temperatures** (25-35°C), leading to faster gas formation - The accumulation of **putrefactive gases** (hydrogen sulfide, methane, carbon dioxide) in body cavities reduces the body's specific gravity, causing it to float - This process typically occurs within **24 hours in warm water**, which is the most commonly observed timeframe in Indian summer conditions - This is a classical teaching point in forensic medicine regarding postmortem changes in water *Incorrect: 8 hours* - **Too short** for sufficient gas accumulation to cause consistent flotation of an adult body - While lighter bodies or those in very warm, shallow water might float earlier, 8 hours is uncommon for typical cases - Initial stages of putrefaction are just beginning at this timeframe *Incorrect: 16 hours* - While plausible in some cases with optimal conditions, **not the most consistent timeframe** for flotation - Gas production is still ongoing but typically insufficient for stable flotation in most adult bodies - Falls short of the classical 24-hour teaching in forensic pathology *Incorrect: 36 hours* - Bodies will certainly be floating by this time, but this represents a **later stage beyond initial flotation** - The critical gas accumulation for flotation usually occurs **within the first 24 hours** in warm water - This timeframe is beyond what is typically considered the initial appearance of flotation

Q: HIV post exposure prophylaxis should be started within?

72 hrs. ***72 hrs*** - **Post-exposure prophylaxis (PEP)** aims to prevent HIV infection after potential exposure and should ideally be initiated as soon as possible, but no later than **72 hours** after exposure [1]. - Starting PEP within this window significantly increases its effectiveness in preventing HIV seroconversion. *1-2 hrs* - While initiating PEP as soon as possible is crucial, stating it must be within **1-2 hours** can be misleading as the window of effectiveness extends beyond this. - This timeframe might be an ideal, but not the absolute crucial limit for efficacy. *14 hrs* - This timeframe is **too restrictive** for the recommended window for PEP initiation. - Missing the opportunity within **14 hours** does not negate the effectiveness of PEP if started within the broader 72-hour window. *18 hrs* - Similar to **14 hours**, **18 hours** is an unnecessarily strict limit for PEP initiation. - Guidelines universally support starting PEP up to **72 hours** post-exposure for optimal benefit [1].

Q: What is a key distinguishing feature of meningococci compared to gonococci?

Ferment maltose. ***Ferment maltose*** - *Neisseria meningitidis* ferments both **glucose and maltose**, which is a key biochemical characteristic used for its identification. - *Neisseria gonorrhoeae* only ferments **glucose**, differentiating it from meningococci. *Are intracellular pathogens* - Both **meningococci** (*Neisseria meningitidis*) and **gonococci** (*Neisseria gonorrhoeae*) are facultative intracellular pathogens, meaning they can survive and replicate within host cells. - Therefore, this feature does not distinguish between the two. *Are catalase positive* - Both *Neisseria meningitidis* and *Neisseria gonorrhoeae* are **catalase-positive**, meaning they produce the enzyme catalase. - This characteristic is common to both and thus cannot be used to differentiate them. *Possess a capsule* - While *Neisseria meningitidis* possesses a **polysaccharide capsule**, which is a major virulence factor, *Neisseria gonorrhoeae* typically **lacks a capsule**. - However, the ability to ferment maltose is a more direct and commonly used biochemical distinguishing feature in laboratory settings.

Q: Which of the following statements about p24 is false?

Cannot be detected after seroconversion. ***Cannot be detected after seroconversion*** - This statement is **FALSE** and is the correct answer to this question. - **p24 antigen levels do decrease** after seroconversion due to immune complex formation with antibodies, but p24 can still be detected using modern assays. - In **advanced HIV disease** with declining CD4 counts, p24 antigen often becomes detectable again due to high viral loads. - Fourth-generation HIV tests detect both antibodies and p24 antigen throughout the infection course. *Cannot be seen in the first week* - This statement is **TRUE** (not the answer). - p24 antigen typically appears around **10-14 days** (1.5-2 weeks) after infection, which is after the first week (days 1-7). - The eclipse period (first 7-10 days) precedes p24 detection. *Can be detected after 3 weeks of infection* - This statement is **TRUE** (not the answer). - p24 antigen is consistently detectable at 3 weeks post-infection during the acute viremic phase. - Peak p24 levels occur around **2-4 weeks** after infection. *All of the above* - This is a distractor option and is incorrect since only one statement is false.

Q: Which of the following viruses is classified as a poxvirus?

Variola. ***Variola virus*** - **Variola virus** is the causative agent of **smallpox**, a historically significant and highly contagious disease. - It belongs to the **Orthopoxvirus** genus within the **Poxviridae family**, characterized by its large, brick-shaped virion and dsDNA genome. *Coxsackie virus* - **Coxsackieviruses** are part of the **Picornaviridae family**, specifically the **Enterovirus** genus. - They are known to cause a range of diseases including **hand-foot-and-mouth disease**, myocarditis, and aseptic meningitis, and are much smaller than poxviruses. *ECHO virus* - **Echoviruses** (Enteric Cytopathic Human Orphan viruses) are also members of the **Picornaviridae family** and the **Enterovirus** genus. - They are associated with diseases such as **aseptic meningitis**, gastroenteritis, and respiratory infections, completely distinct from poxviruses. *HSV (Herpes Simplex Virus)* - **Herpes Simplex Viruses** belong to the **Herpesviridae family**, characterized by a **linear dsDNA genome** and an enveloped icosahedral capsid. - They cause diseases like **oral and genital herpes** and are structurally and genetically distinct from poxviruses.

Q: What is the most common cause of anterior uveitis?

Idiopathic. ***Idiopathic*** - In a significant proportion of cases of **anterior uveitis**, a specific cause cannot be identified, leading to a diagnosis of idiopathic uveitis. - This highlights the multifactorial nature of the condition, where various triggers or underlying predispositions may not always be evident. *CMV* - **Cytomegalovirus (CMV)** typically causes a **posterior uveitis** or **retinitis**, especially in immunocompromised individuals. - While CMV can rarely cause anterior uveitis, it is not the most common cause. *Toxoplasma* - **Toxoplasmosis** is a frequent cause of **posterior uveitis** or **chorioretinitis**, characterized by focal necrotic lesions in the retina. - It is not a common cause of isolated anterior uveitis, although anterior chamber inflammation can occur secondary to posterior disease. *Ankylosing spondylitis* - **Ankylosing spondylitis** is a well-known systemic condition associated with **acute anterior uveitis**. - However, while a significant association exists, it is not the single most common cause when considering all cases of anterior uveitis, many of which remain idiopathic.

Q: Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Alprostadil. ***Alprostadil***- **Alprostadil** is a **prostaglandin E1** analog that can directly induce vasodilation in the penile arteries, leading to an erection without sexual stimulation [1].- It is typically administered via **intracavernosal injection** or as a **urethral suppository**.*Sildenafil*- **Sildenafil** is a **PDE5 inhibitor** that works by enhancing the effects of **nitric oxide**, which is released in response to sexual stimulation [2, 3].- It requires **sexual arousal** to be effective, as it doesn't directly initiate the erectile process [2, 3].*Tadalafil*- Similar to sildenafil, **tadalafil** is also a **PDE5 inhibitor** that works by increasing cGMP levels and promoting smooth muscle relaxation [2, 3].- Its action is dependent on the release of **nitric oxide** triggered by sexual stimulation [2, 3].*Testosterone*- **Testosterone** is a hormone involved in sex drive and overall erectile function over time, but it does not directly or acutely induce an erection.- Its primary role in erectile dysfunction is in cases of **hypogonadism**, and it requires sexual stimulation for its effects on erection.

Q: Which steroid has the maximum mineralocorticoid activity?

Fludrocortisone. ***Fludrocortisone*** - **Fludrocortisone** is a synthetic corticosteroid specifically designed to have potent **mineralocorticoid activity**, with significant sodium-retaining properties. - Its high affinity for **mineralocorticoid receptors** distinguishes it from other steroids and makes it effective in treating conditions like **Addison's disease** and **postural orthostatic tachycardia syndrome (POTS)** due to its ability to retain sodium and water. *DOCA (Deoxycorticosterone acetate)* - While **DOCA** does possess significant **mineralocorticoid activity** and was historically used for this purpose, **fludrocortisone** is generally considered to have a stronger and more sustained effect in clinical practice. - **DOCA's** mineralocorticoid potency is substantial but slightly less than that of **fludrocortisone** when compared on a weight basis for equivalent sodium retention. *Prednisolone* - **Prednisolone** is primarily a **glucocorticoid** with potent anti-inflammatory and immunosuppressive effects. - It has minimal to negligible **mineralocorticoid activity** and is not used for salt retention purposes. *Triamcinolone* - **Triamcinolone** is a potent **glucocorticoid** with a long duration of action and is known for its strong anti-inflammatory properties. - It has virtually no **mineralocorticoid activity**, making it unsuitable for conditions requiring sodium retention.

Question 1

Which is the main vector of Dengue?

Accepted Answer

A. aegypti

Answer

Culex

Answer

Anopheles

Answer

Aedes scutellaris

Question 2

All of the following are characteristics of case control study except:

Accepted Answer

Measures incidence rate

Answer

Quick results are obtained

Answer

Inexpensive study

Answer

Proceeds from effect to cause

Question 3

What is the estimated time for a dead body to float in water under typical summer conditions in India, considering various influencing factors?

Accepted Answer

24 hours

Answer

8 hours

Answer

16 hours

Answer

36 hours

Question 4

HIV post exposure prophylaxis should be started within?

Accepted Answer

72 hrs

Answer

1-2 hrs

Answer

14 hrs

Answer

18 hrs

Question 5

What is a key distinguishing feature of meningococci compared to gonococci?

Accepted Answer

Ferment maltose

Answer

Are intracellular pathogens

Answer

Are catalase positive

Answer

Possess a capsule

Question 6

Which of the following statements about p24 is false?

Accepted Answer

Cannot be detected after seroconversion

Answer

Cannot be seen in the first week

Answer

All of the above

Answer

Can be detected after 3 weeks of infection

Question 7

Which of the following viruses is classified as a poxvirus?

Accepted Answer

Variola

Answer

Coxsackie

Answer

ECHO

Answer

HSV

Question 8

What is the most common cause of anterior uveitis?

Accepted Answer

Idiopathic

Answer

CMV

Answer

Toxoplasma

Answer

Ankylosing spondylitis

Question 9

Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Accepted Answer

Alprostadil

Answer

Sildenafil

Answer

Tadalafil

Answer

Testosterone

Question 10

Which steroid has the maximum mineralocorticoid activity?

Accepted Answer

Fludrocortisone

Answer

DOCA

Answer

Prednisolone

Answer

Triamcinolone

NEET-PG 2012

Community Medicine

Forensic Medicine

Internal Medicine

Microbiology

Ophthalmology

Pharmacology