Internal Medicine
1 questionsSerological testing of patient shows HBsAg, IgM anti-HBc and HBeAg positive. The patient has -
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 471: Serological testing of patient shows HBsAg, IgM anti-HBc and HBeAg positive. The patient has -
- A. Acute hepatitis B with high infectivity (Correct Answer)
- B. Chronic hepatitis with high infectivity
- C. Acute on chronic hepatitis
- D. Chronic hepatitis B with low infectivity (not acute)
Explanation: ***Acute hepatitis B with high infectivity*** - The presence of **HBsAg** (hepatitis B surface antigen) indicates active infection, while **IgM anti-HBc** (IgM antibody to hepatitis B core antigen) is a marker of recent or acute infection [1]. - **HBeAg** (hepatitis B e-antigen) positivity signifies active viral replication and a high likelihood of infectivity [1]. *Chronic hepatitis B with low infectivity (not acute)* - **Chronic hepatitis B** is characterized by the presence of **HBsAg for more than six months**, but **IgM anti-HBc** would typically be negative; instead, **IgG anti-HBc** would be positive [1]. - **Low infectivity** would be indicated by the absence of **HBeAg**, replaced by **anti-HBe** (antibody to HBeAg) [1]. *Chronic hepatitis with high infectivity* - This diagnosis would show positive **HBsAg and HBeAg**, but the absence of **IgM anti-HBc** (presence of **IgG anti-HBc** instead) would distinguish it from acute infection [1]. - The presence of **IgM anti-HBc** is a crucial marker for an acute phase of hepatitis B rather than chronic. *Acute on chronic hepatitis* - This scenario would involve a patient with pre-existing **chronic hepatitis B** (positive HBsAg, IgG anti-HBc) experiencing a new acute flare-up, which could involve a resurgence of **HBeAg** or a new acute viral insult. - While **HBsAg** and **HBeAg** would be positive, the key differentiator would be the presence of both **IgM anti-HBc** (indicating the acute component) and **IgG anti-HBc** (indicating the chronic component), which is not fully described here to confirm acute on chronic.
Microbiology
6 questionsWhich of the following is a member of the kingdom Protista?
Katayama fever is caused by which of the following?
Necrotizing fasciitis is caused by -
The gene encoding cholera toxin is carried on -
Unsegmented eggs are in which parasite?
Which of the following substances is toxic to parasites?
NEET-PG 2012 - Microbiology NEET-PG Practice Questions and MCQs
Question 471: Which of the following is a member of the kingdom Protista?
- A. Fungi
- B. Protozoa (Correct Answer)
- C. Bacteria
- D. Virus
Explanation: ***Protozoa*** - **Protozoa** are single-celled eukaryotic organisms that are heterotrophic and typically motile, fitting the classification within the kingdom Protista. - Protista is a **diverse kingdom** encompassing various eukaryotic organisms that are not animals, plants, or fungi, and protozoa represent the animal-like protists. - Examples include **Amoeba, Plasmodium, Giardia**, and Entamoeba. *Virus* - **Viruses** are not classified within any kingdom as they are **acellular** (not made of cells). - They are obligate intracellular parasites that require a host cell to replicate. - Lack cellular machinery and metabolic processes that define living organisms. *Fungi* - **Fungi** belong to their own distinct kingdom, Fungi, and are not classified under Protista. - They are **heterotrophic eukaryotes** that absorb nutrients and have cell walls made of chitin. - Examples include yeasts, molds, and mushrooms. *Bacteria* - **Bacteria** are prokaryotic organisms, meaning they lack a membrane-bound nucleus and other membrane-bound organelles. - They belong to the kingdom **Monera** (or domain Bacteria in modern classification), separate from eukaryotic kingdoms like Protista. - They have peptidoglycan cell walls and reproduce by binary fission.
Question 472: Katayama fever is caused by which of the following?
- A. F. hepatica
- B. C. sinensis
- C. A. lumbricoides
- D. S. japonicum (Correct Answer)
Explanation: ***Correct: S. japonicum*** - Katayama fever, also known as **acute schistosomiasis**, is a systemic hypersensitivity reaction to the migrating schistosomula and oviposition of eggs that primarily occurs in infections with **_Schistosoma japonicum_** or _S. mansoni_. - It presents with fever, chills, cough, diarrhea, abdominal pain, hepatosplenomegaly, and eosinophilia, typically 2-8 weeks after exposure to contaminated water. - S. japonicum tends to cause the most severe form of Katayama fever. *Incorrect: F. hepatica* - **_Fasciola hepatica_** causes fascioliasis, an infection of the bile ducts and liver, which can present with fever and eosinophilia, but it does not typically cause the acute systemic reaction known as Katayama fever. - The disease is usually acquired by ingesting **metacercariae** on aquatic vegetation or in contaminated water. *Incorrect: C. sinensis* - **_Clonorchis sinensis_** is the Chinese liver fluke, causing clonorchiasis, an infection primarily of the bile ducts. - Symptoms are often mild or asymptomatic but can include abdominal pain, indigestion, diarrhea, and jaundice in heavy infections, without the distinct acute systemic syndrome of Katayama fever. *Incorrect: A. lumbricoides* - **_Ascaris lumbricoides_** is a roundworm that causes ascariasis, primarily affecting the gastrointestinal tract. - While it can cause pulmonary symptoms during larval migration (Löffler's syndrome), it does not cause Katayama fever, which is specific to schistosomiasis.
Question 473: Necrotizing fasciitis is caused by -
- A. Beta hemolytic streptococci (Correct Answer)
- B. Pneumococcus
- C. Staphylococcus aureus
- D. Clostridium perfringens
Explanation: ***Beta hemolytic streptococci*** - **Group A Streptococcus (GAS)**, specifically *Streptococcus pyogenes*, is the most common cause of **Type II necrotizing fasciitis**. - Its virulence factors, like **exotoxins**, contribute to rapid tissue destruction and systemic toxicity. *Staphylococcus aureus* - While *S. aureus* can cause severe skin and soft tissue infections, it is more commonly associated with **cellulitis**, **abscesses**, and **septic arthritis**. - It can be a co-pathogen in **polymicrobial (Type I) necrotizing fasciitis** but is less frequent as a sole cause compared to GAS for Type II. *Pneumococcus* - *Streptococcus pneumoniae* (Pneumococcus) is primarily known for causing respiratory infections like **pneumonia**, **otitis media**, and **meningitis**. - It is not a typical causative agent of necrotizing fasciitis. *Clostridium perfringens* - This bacterium is the primary cause of **gas gangrene** (clostridial myonecrosis), a severe form of necrotizing soft tissue infection involving muscle tissue. - While also a flesh-eating bacterium, its clinical presentation and typical affected tissues differ from those of necrotizing fasciitis caused by streptococci.
Question 474: The gene encoding cholera toxin is carried on -
- A. Chromosomal DNA
- B. Extrachromosomal plasmid
- C. Bacteriophage (Correct Answer)
- D. Transposon
Explanation: ***Bacteriophage*** - The gene encoding **cholera toxin (ctxA and ctxB)** is carried on the genome of a **lysogenic bacteriophage** known as CTXf. - This phage integrates its DNA into the *Vibrio cholerae* chromosome, allowing for toxin production. *Chromosomal DNA* - While the **phage DNA (containing the cholera toxin gene)** integrates into the *Vibrio cholerae* chromosome, the toxin itself is **not directly encoded by the core bacterial chromosomal DNA** but by the integrated phage DNA. - Many bacterial virulence factors are encoded on the main chromosome, but cholera toxin is a specific exception. *Extrachromosomal plasmid* - **Plasmids** are extrachromosomal DNA molecules that can carry virulence genes, but the cholera toxin gene is **not typically found on a plasmid** in *Vibrio cholerae*. - Examples of plasmid-encoded toxins include some enterotoxins in *E. coli*. *Transposon* - **Transposons** are "jumping genes" that can move within and between DNA molecules, but they are generally **mobile genetic elements** that carry genes, not the direct source of the cholera toxin gene. - While transposons can sometimes contribute to the movement of virulence genes, the cholera toxin gene specifically originates from a bacteriophage.
Question 475: Unsegmented eggs are in which parasite?
- A. Ancylostoma
- B. Necator americanus
- C. Dracunculus
- D. Trichuris trichiura (Correct Answer)
Explanation: ***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.
Question 476: Which of the following substances is toxic to parasites?
- A. Peroxidase (Correct Answer)
- B. Interferon-alpha
- C. IL-2 (Interleukin-2)
- D. IL-6 (Interleukin-6)
Explanation: ***Peroxidase*** - **Peroxidase** enzymes, especially those produced by **eosinophils**, generate toxic oxygen metabolites and hypohalous acids that are highly effective at damaging and killing parasites. - This enzyme plays a crucial role in the host's defense against larger parasites, such as **helminths (worms)**. *Interferon-alpha* - **Interferon-alpha** is an important cytokine primarily known for its **antiviral effects** and its role in activating natural killer (NK) cells. - While it modulates immune responses, it does not directly act as a toxic substance to parasites. *IL-2 (Interleukin-2)* - **IL-2** is a growth factor that primarily promotes the **proliferation and differentiation of T cells**, enhancing adaptive immune responses. - It does not directly kill parasites but rather supports the immune cells involved in parasite clearance. *IL-6 (Interleukin-6)* - **IL-6** is a pleiotropic cytokine involved in **inflammation, acute phase responses**, and the differentiation of B cells and T cells. - While it contributes to overall immune regulation, it lacks direct parasiticidal activity.
Obstetrics and Gynecology
1 questionsRule of Hasse is used to determine :
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 471: Rule of Hasse is used to determine :
- A. Height of an adult.
- B. Race of a person.
- C. Identification of fetal abnormalities.
- D. Age of the fetus (Correct Answer)
Explanation: ***Age of the fetus*** - **Hasse's Rule** is a forensic pathology method used to estimate the **age of a dead fetus** (stillborn or aborted fetus) based on its physical length. - The rule states: **For months 1-5**: Age in months = Length in cm; **For months 6-10**: Age in months = Length in cm ÷ 5 - This is primarily used in **medico-legal contexts** and post-mortem examinations, not in routine obstetric practice. - The measurement is taken from **crown to heel** of the deceased fetus. *Height of an adult* - Hasse's Rule is specifically for estimating **fetal age** in forensic settings, not for determining adult height. - Adult height is determined by genetics, nutrition, and growth patterns during development. *Race of a person* - This rule is used solely for **fetal age estimation** in post-mortem examinations. - It has no application in determining racial characteristics. *Identification of fetal abnormalities* - Hasse's Rule is a **dating method** for deceased fetuses, not a diagnostic tool for abnormalities. - Fetal abnormalities are identified through detailed anatomical examination, imaging studies, and other specific diagnostic methods.
Ophthalmology
1 questionsToxoplasma in children causes:
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 471: Toxoplasma in children causes:
- A. Chorioretinitis (Correct Answer)
- B. Keratitis
- C. Papillitis
- D. Conjunctivitis
Explanation: ***Chorioretinitis*** - **Toxoplasmosis** is a significant cause of **chorioretinitis** in children, particularly congenital infections. - Ocular toxoplasmosis often presents with **retinal lesions** that can lead to vision loss. *Conjunctivitis* - **Conjunctivitis** is an inflammation of the conjunctiva, typically caused by bacterial or viral infections. - While it can occur in children, it is not a primary or characteristic manifestation of **Toxoplasma infection**. *Keratitis* - **Keratitis** is an inflammation of the cornea, often caused by bacterial, viral, or fungal infections, or sometimes trauma. - Although eyes are affected by **Toxoplasma**, **keratitis** is not the typical ophthalmic presentation; **chorioretinitis** is. *Papillitis* - **Papillitis** refers to inflammation of the optic disc (optic nerve head). - While **Toxoplasma** can rarely affect the optic nerve, **papillitis** is not the most common or specific ocular manifestation compared to **chorioretinitis**.
Pediatrics
1 questionsCongenital varicella infection causes all except:
NEET-PG 2012 - Pediatrics NEET-PG Practice Questions and MCQs
Question 471: Congenital varicella infection causes all except:
- A. Macrocephaly (Correct Answer)
- B. Cortical atrophy
- C. Cicatrix
- D. Limb hypoplasia
Explanation: ***Macrocephaly*** - **Macrocephaly** is generally not a direct consequence of congenital varicella infection; rather, **microcephaly** due to brain damage is more commonly observed. - Congenital varicella typically causes destructive lesions leading to tissue loss, not increased head circumference. *Cortical atrophy* - **Cortical atrophy** results from the destructive effects of the virus on the developing brain, leading to **neuronal loss** and reduced brain volume. - This can manifest as **microcephaly**, an indirect but common finding associated with congenital varicella. *Cicatrix* - **Cicatrix** (zig-zag scarring) is a classic dermatological manifestation of congenital varicella, resulting from the virus's impact on developing skin. - These characteristic **skin lesions** are one of the most identifiable features of the syndrome. *Limb hypoplasia* - **Limb hypoplasia**, involving underdeveloped limbs, is a hallmark feature of congenital varicella, often due to **viral damage** to limb buds and associated neural structures. - This can lead to **bone shortening** and muscle atrophy in affected limbs.