Biochemistry
1 questionsMechanism of cyanide poisoning is by inhibiting: NEET 2013
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 451: Mechanism of cyanide poisoning is by inhibiting: NEET 2013
- A. DNA synthesis
- B. Cytochrome oxidase (Correct Answer)
- C. Protein breakdown
- D. Protein synthesis
Explanation: ***Cytochrome oxidase*** - **Cyanide** is a potent poison because it binds to the **ferric iron (Fe3+)** in the active site of **cytochrome c oxidase**. - This binding completely inhibits the enzyme, halting **cellular respiration** and **ATP production**, leading to rapid cell death. *DNA synthesis* - **Cyanide** does not directly inhibit **DNA polymerase** or other enzymes involved in DNA replication. - While overall cellular processes are disrupted, its primary toxic effect is not on DNA synthesis. *Protein breakdown* - **Cyanide** does not directly interfere with proteasomes or lysosomal enzymes responsible for **protein degradation**. - Its mechanism of action is upstream, affecting energy production necessary for all cellular processes, including protein turnover. *Protein synthesis* - **Cyanide** does not directly inhibit **ribosomes** or the enzymatic machinery for **protein synthesis**. - The lack of **ATP** caused by cyanide poisoning would eventually shut down protein synthesis, but this is a secondary effect, not the primary mechanism of action.
Community Medicine
1 questionsWhat is the common adulterant found in black pepper?
NEET-PG 2012 - Community Medicine NEET-PG Practice Questions and MCQs
Question 451: What is the common adulterant found in black pepper?
- A. Khesari dal
- B. Fine sand
- C. None of the options
- D. Dried papaya seeds (Correct Answer)
Explanation: ***Dried papaya seeds*** - **Dried papaya seeds** are a common adulterant in black pepper due to their similar size, shape, and color, making them difficult to distinguish visually. - Adulteration with papaya seeds is often done to increase the bulk and weight of the black pepper product, thereby reducing production costs. *Khesari dal* - **Khesari dal (Lathyrus sativus)** is a type of lentil known for causing **lathyrism**, a neurotoxic disorder, but it is not typically used to adulterate black pepper. - Its appearance and texture are distinctly different from black pepper, making it an unsuitable adulterant. *Fine sand* - **Fine sand** can be an adulterant in spices, but it is more commonly found in powdered spices like chilli powder or turmeric due to its fine particle size. - While it adds weight, its presence in whole black pepper would be easily detectable due to its abrasive texture and grittiness. *None of the options* - This option is incorrect because **dried papaya seeds** are a well-documented and common adulterant in black pepper. - The similarities in appearance make it a frequent choice for unscrupulous suppliers.
Dermatology
1 questionsWhich of the following statements is true regarding donovanosis?
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 451: Which of the following statements is true regarding donovanosis?
- A. Pseudolymphadenopathy is characteristic
- B. Penicillin is used for treatment
- C. Painful ulcer is characteristic
- D. Painless ulcerative lesions are characteristic of donovanosis (Correct Answer)
Explanation: ***Painless ulcerative lesions are characteristic of donovanosis*** - Donovanosis, also known as granuloma inguinale, is characterized by **painless, progressive ulcerative lesions** that can bleed easily. - The lesions typically start as papules or nodules and then erode to form **granulomatous ulcers** with a beefy red appearance. - This is a key distinguishing feature from chancroid (painful ulcers) and primary syphilis. *Pseudolymphadenopathy is characteristic* - While donovanosis can lead to swelling in the inguinal region, it's typically **pseudobuboes** (subcutaneous granulomas) rather than true lymphadenopathy. - However, this is not a defining characteristic, as pseudobuboes are less common and occur in advanced cases. - The primary feature remains the **painless ulcerative lesions**. *Penicillin is used for treatment* - **Penicillin** is not the standard treatment for donovanosis; it is ineffective against *Klebsiella granulomatis*. - The recommended treatment involves **macrolides** (e.g., azithromycin) or **tetracyclines** (e.g., doxycycline) for at least 3 weeks or until lesions heal. - Alternative regimens include **cotrimoxazole** or **fluoroquinolones**. *Painful ulcer is characteristic* - Donovanosis ulcers are typically **painless**, which distinguishes them from other genital ulcers like those seen in herpes or chancroid. - The **lack of pain** often contributes to delayed presentation and progression of the disease.
Forensic Medicine
3 questionsColor of postmortem lividity in hypothermic deaths: NEET 2012
What is the estimated time for a dead body to float in water under typical summer conditions in India, considering various influencing factors?
What does the term 'vitriolage' refer to in a medical context?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 451: Color of postmortem lividity in hypothermic deaths: NEET 2012
- A. Purple
- B. Deep red
- C. Cherry red
- D. Bright pink (Correct Answer)
Explanation: ***Bright pink*** - In **hypothermic deaths**, postmortem lividity characteristically appears **bright pink** due to **increased oxygen affinity of hemoglobin at lower temperatures**. - At cold temperatures, hemoglobin retains oxygen more tightly, resulting in well-oxygenated blood that produces a pinkish hue in dependent areas. - This is considered a **characteristic finding** in deaths due to cold exposure and hypothermia. *Purple* - **Purple lividity** is the **typical/classical color** seen in most deaths due to pooling of deoxygenated blood (reduced hemoglobin). - While this is the general appearance of livor mortis, it is **not specific** to hypothermic deaths. - Purple represents the baseline color, whereas bright pink is the distinguishing feature in hypothermia. *Deep red* - Deep red lividity may occur with well-oxygenated blood but is not specifically characteristic of hypothermia. - This color variation depends on general oxygenation status rather than cold-specific mechanisms. *Cherry red* - **Cherry red livor mortis** is a classic sign of **carbon monoxide poisoning** or **cyanide poisoning**. - Carboxyhemoglobin (in CO poisoning) produces a characteristic bright cherry red color. - This is unrelated to hypothermic deaths.
Question 452: What is the estimated time for a dead body to float in water under typical summer conditions in India, considering various influencing factors?
- A. 8 hours
- B. 16 hours
- C. 24 hours (Correct Answer)
- D. 36 hours
Explanation: ***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
Question 453: What does the term 'vitriolage' refer to in a medical context?
- A. The act of using vitriol to harm someone.
- B. The act of throwing sulfuric acid at someone. (Correct Answer)
- C. The act of causing harm through chemical means.
- D. The act of poisoning someone with toxic substances.
Explanation: ***The act of throwing sulfuric acid at someone.*** - **Vitriolage** specifically refers to an assault where **sulfuric acid** (historically called **oil of vitriol**) is used to disfigure or injure someone. - This practice is a severe form of **acid attack**, often resulting in extensive burns, disfigurement, and permanent damage. *The act of using vitriol to harm someone.* - While correct in a broad sense, this option is less specific. **Vitriol** refers specifically to sulfuric acid, and the act of vitriolage implies *throwing* it, rather than just "using" it broadly. - The term specifically highlights the **assaultive nature** and the characteristic manner of injury. *The act of causing harm through chemical means.* - This definition is too general; vitriolage is a particular type of chemical harm. There are many other ways to cause chemical harm (e.g., poisoning, chemical burns from other substances) that are not considered vitriolage. - The term is historically and medically tied to the use of a specific corrosive substance: **sulfuric acid**. *The act of poisoning someone with toxic substances.* - Poisoning typically involves *ingestion* or *internal exposure* to toxic substances, leading to systemic effects. - **Vitriolage** refers to *external application* (throwing) of a highly corrosive substance, causing localized and severe tissue damage rather than systemic poisoning.
Microbiology
3 questionsWho discovered the malarial parasite?
How many flagella does Helicobacter pylori typically have?
Which of the following statements is false regarding yersiniosis?
NEET-PG 2012 - Microbiology NEET-PG Practice Questions and MCQs
Question 451: Who discovered the malarial parasite?
- A. Ronald Ross
- B. Paul Muller
- C. Charles Louis Alphonse Laveran (Correct Answer)
- D. Pampania
Explanation: ***Charles Louis Alphonse Laveran*** - **Charles Louis Alphonse Laveran** was a French physician who, in **1880**, observed parasites in the blood of a malaria patient. - He was awarded the **Nobel Prize in Physiology or Medicine in 1907** for his discovery of the role of protozoa in causing diseases, specifically recognizing the malarial parasite. *Ronald Ross* - **Ronald Ross** was a British physician who, in **1897**, demonstrated that **malaria is transmitted by mosquitoes**. - While he elucidated the **transmission cycle**, it was Laveran who first identified the parasite itself in human blood. - He received the **Nobel Prize in 1902** for this work. *Paul Muller* - **Paul Muller** was a Swiss chemist who was awarded the **Nobel Prize in Physiology or Medicine in 1948** for his discovery of the insecticidal properties of **DDT (dichlorodiphenyltrichloroethane)**. - His work was significant in combating insect-borne diseases like malaria, but he was not involved in the discovery of the malarial parasite. *Pampania* - This name does not correspond to any recognized figure in the discovery of the malarial parasite or its transmission. - This is a distractor option in the original examination question.
Question 452: How many flagella does Helicobacter pylori typically have?
- A. 4-6 (Correct Answer)
- B. 3
- C. 2
- D. 1
Explanation: ***4-6*** - *Helicobacter pylori* is characterized by having **multiple flagella** (typically 4-6) at one pole, which are crucial for its motility. - These flagella allow the bacterium to move through the viscous gastric mucus layer and colonize the gastric epithelium. *1* - While some bacteria, like *Vibrio cholerae*, may possess a single polar flagellum, this is not characteristic of *Helicobacter pylori*. - A single flagellum would provide less efficient motility in the challenging environment of the stomach. *2* - Having two flagella is not the typical configuration for *Helicobacter pylori*. - Many bacteria have varied flagellar arrangements, but two is not representative of this particular bacterium. *3* - Three flagella is an insufficient number for the characteristic motility and colonization strategy of *Helicobacter pylori*. - **Lophotrichous** flagella typically refers to a tuft of multiple flagella, consistent with 4-6.
Question 453: Which of the following statements is false regarding yersiniosis?
- A. Gram-negative bacillus
- B. Caused by Yersinia pseudotuberculosis
- C. Caused by Yersinia pestis (Correct Answer)
- D. Caused by Yersinia enterocolitica
Explanation: ***Caused by Yersinia pestis*** - **Yersinia pestis** is the causative agent of **plague**, not typical yersiniosis affecting the gastrointestinal tract. - Yersiniosis generally refers to infections caused by other *Yersinia* species like *Y. enterocolitica* and *Y. pseudotuberculosis*. *Gram-negative bacillus* - *Yersinia* species, including *Y. enterocolitica* and *Y. pseudotuberculosis*, are indeed **Gram-negative bacilli**. - This characteristic is fundamental to their classification and bacterial structure. *Caused by Yersinia pseudotuberculosis* - **Yersinia pseudotuberculosis** is a recognized cause of **yersiniosis**, particularly affecting children. - It can cause symptoms such as **abdominal pain** and **mesenteric lymphadenitis**, mimicking appendicitis. *Caused by Yersinia enterocolitica* - **Yersinia enterocolitica** is the **most common cause of yersiniosis** in humans. - It is responsible for a range of symptoms including **gastroenteritis**, **acute enteritis**, and **mesenteric lymphadenitis**.
Psychiatry
1 questionsWhat is the most commonly abused drug in India?
NEET-PG 2012 - Psychiatry NEET-PG Practice Questions and MCQs
Question 451: What is the most commonly abused drug in India?
- A. Heroin
- B. Amphetamine
- C. Cocaine
- D. Cannabis (Correct Answer)
Explanation: ***Cannabis*** - Cannabis (bhang, ganja, charas) is the **most commonly abused illicit drug in India** according to national surveys including the National Survey on Extent and Pattern of Substance Use. - It has **widespread social and cultural acceptance** in certain contexts, contributing to its higher prevalence across diverse populations. - Cannabis use is distributed across **all socioeconomic strata** and geographic regions, making it more prevalent than other illicit drugs. *Heroin* - While heroin is a **highly addictive opioid** with severe health consequences, its overall prevalence is **lower than cannabis** at the national level. - Heroin abuse is more concentrated in **specific regions** (northern states like Punjab, northeastern states) rather than being uniformly distributed. - The National Survey data shows opioid abuse (including heroin) affects a **smaller percentage** of the population compared to cannabis. *Amphetamine* - Amphetamines are **stimulant drugs** that are significantly less commonly abused in India compared to cannabis and opioids. - Their use is **highly localized** and represents a much smaller proportion of substance abuse cases. *Cocaine* - Cocaine is a **powerful stimulant** that is expensive and less accessible in India, making it one of the **least commonly abused** drugs. - Its use is typically limited to **affluent urban populations** and represents minimal prevalence in national substance abuse statistics.