Anatomy
1 questionsCrural index is:
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 681: Crural index is:
- A. Length of tibia/femur x 100 (Correct Answer)
- B. Length of radius/humerus x 100
- C. Length of fibula/tibia x 100
- D. Length of radius/ulna x 100
Explanation: ***Length of tibia/femur x 100*** - The **crural index** is a measure used in physical anthropology and comparative anatomy to describe the proportion of the lower leg to the thigh. - It is calculated by dividing the **length of the tibia** (lower leg bone) by the **length of the femur** (thigh bone) and multiplying by 100 to express it as a percentage. *Length of radius/humerus x 100* - This formula describes the **brachial index**, which measures the proportion of the forearm to the upper arm. - It does not represent the crural index, which refers specifically to the **lower limb**. *Length of fibula/tibia x 100* - This ratio compares the two bones within the lower leg but is not the definition of the **crural index**. - The crural index focuses on the relative length of the lower leg to the entire thigh, reflecting overall **limb proportions**. *Length of radius/ulna x 100* - This ratio compares the lengths of the two bones in the forearm and does not correspond to the **crural index**. - The crural index involves the **tibia** and **femur**, which are bones of the lower limb.
Community Medicine
1 questionsThe primary reservoir for leptospirosis transmission is:
NEET-PG 2012 - Community Medicine NEET-PG Practice Questions and MCQs
Question 681: The primary reservoir for leptospirosis transmission is:
- A. Rat (Correct Answer)
- B. Cat
- C. Dog
- D. Fish
Explanation: ***Correct Answer: Rat*** - **Rats** (and other rodents) are considered the primary natural reservoir for *Leptospira* bacteria worldwide and are **asymptomatic carriers**. - They excrete the bacteria in their urine, contaminating water and soil, which serves as the main source of human infection. *Incorrect: Cat* - While cats can become infected with *Leptospira*, they are **not typically considered significant reservoirs** for human transmission. - Their role in the epidemiologic cycle of leptospirosis is generally minor compared to rodents and some other mammals. *Incorrect: Dog* - **Dogs** can contract leptospirosis and excrete the bacteria in their urine, posing a risk to humans, but they are generally considered **incidental hosts or secondary reservoirs**, not the primary one. - Vaccination in dogs helps reduce their role in transmission. *Incorrect: Fish* - **Fish are not known to be reservoirs** for *Leptospira* bacteria. - Leptospirosis is primarily transmitted through contact with infected animal urine, not aquatic life like fish.
Forensic Medicine
4 questionsWhat is the first external sign of decomposition of a dead body?
Dirt collar or grease collar is seen in which type of wound?
Disputed maternity can be solved by using the following tests, EXCEPT:
Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 681: What is the first external sign of decomposition of a dead body?
- A. Decomposition of liver and intestine
- B. Greenish discolouration over right iliac fossa (Correct Answer)
- C. Greenish discolouration over dependent parts
- D. Blood stained froth from mouth
Explanation: ***Greenish discolouration over right iliac fossa*** - The **first external sign of decomposition** is typically a **greenish discoloration** that appears over the **right iliac fossa**. - This occurs due to the breakdown of **hemoglobin** by bacteria, particularly *Clostridium perfringens*, in the **cecum**, which is located in this region. - It typically appears **12-24 hours after death** under normal environmental conditions. *Decomposition of liver and intestine* - While internal organs like the liver and intestine do decompose, their decomposition is an **internal process** and not the **first external sign**. - Internal putrefaction precedes external signs but is not visually observable from the exterior initially. *Greenish discolouration over dependent parts* - Greenish discolouration over dependent parts represents a **later stage of decomposition** when putrefactive changes spread throughout the body. - This occurs after the initial greenish discoloration in the right iliac fossa as bacterial action and gases spread from the intestines to other body regions. - This is NOT the first external sign but rather a progression of decomposition. *Blood stained froth from mouth* - **Blood-stained froth from the mouth** can be seen in various conditions, such as **drowning**, **pulmonary edema**, or certain types of poisoning, but it is not related to decomposition. - This finding is more indicative of the cause of death or agonal/perimortem changes rather than postmortem decomposition.
Question 682: Dirt collar or grease collar is seen in which type of wound?
- A. Lacerated wound
- B. Firearm entry wound (Correct Answer)
- C. Stab wound
- D. Punctured wound by sharp weapon
Explanation: ***Firearm entry wound*** - A **dirt collar** or **grease collar** is a characteristic finding in a **firearm entry wound**, caused by the wiping off of dirt, lubricant, and other residues from the projectile as it penetrates the skin. - This reddish-brown to black ring around the wound entrance is a crucial indicator of the **direction of fire** and the nature of the injury. *Punctured wound by sharp weapon* - This type of wound is characterized by a small, deep opening caused by a sharp, pointed object, and typically lacks the **residue collection** that forms a dirt or grease collar. - While there may be some contamination, it does not form a distinct, recognizable collar as seen with firearm projectiles. *Lacerated wound* - A lacerated wound is an irregular tear in the skin caused by a blunt force trauma, characterized by **jagged edges** and often bridging tissue. - These wounds are not typically associated with a "dirt collar" as they are due to tearing rather than a projectile wiping off material. *Stab wound* - A stab wound is caused by a sharp object penetrating the skin, with depth greater than width, and is defined by its clean-cut edges. - While there might be some *foreign material* deposited, it does not present as a distinct **grease or dirt collar** because the mechanism of injury (cutting/stabbing) differs from that of a bullet.
Question 683: Disputed maternity can be solved by using the following tests, EXCEPT:
- A. Blood grouping
- B. HLA typing
- C. DNA fingerprinting
- D. Precipitin test (Correct Answer)
Explanation: ***Precipitin test*** - The **precipitin test** is used to determine the origin of a **blood sample**, specifically whether it is **human or animal blood**, by detecting species-specific proteins. It is not used for assessing maternity. - This test is primarily employed in **forensic serology** to differentiate between blood from different animal species, making it irrelevant for paternity or maternity disputes. *Blood grouping* - **Blood grouping** (e.g., ABO and Rh systems) can be used to **exclude paternity or maternity** by comparing the blood types of the child, mother, and alleged father. - If the child's blood type is incompatible with the alleged parents based on Mendelian inheritance, one or both can be excluded. *HLA typing* - **HLA typing** (Human Leukocyte Antigen) is a more powerful genetic marker system than ABO/Rh for determining paternity or maternity. - It involves analyzing highly polymorphic genes on chromosome 6 that encode cell surface proteins, providing a more definitive means of **inclusion or exclusion**. *DNA fingerprinting* - **DNA fingerprinting** (also known as **DNA profiling**) is the **most accurate and widely accepted method** for resolving paternity and maternity disputes. - It analyzes highly variable regions of DNA unique to each individual, providing a statistically strong basis for **inclusion or exclusion** by comparing genetic profiles.
Question 684: Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
- A. Saliva
- B. Tooth
- C. Buccal mucosa
- D. Blood (Correct Answer)
Explanation: ***Blood*** - **Blood** provides a high concentration of **nucleated cells** (e.g., white blood cells), yielding abundant and high-quality DNA. - The DNA obtained from blood is typically well-preserved and less prone to degradation or contamination compared to other sources. *Saliva* - While saliva contains DNA from **buccal epithelial cells** and white blood cells, its DNA yield can be lower and more variable due to mucous and bacterial contamination. - DNA from saliva may be more subject to degradation, especially if not collected and stored properly. *Tooth* - **Teeth** can be a good source of DNA, particularly from the **pulp**, but extraction can be challenging and destructive. - The DNA yield varies depending on the tooth's condition and the extraction method, and it is generally reserved for situations where other sources are unavailable or severely degraded. *Buccal mucosa* - **Buccal mucosa** swabs are a common and non-invasive source of DNA from **epithelial cells**. - While suitable for many applications, the DNA yield can be lower than blood, and the sample may be more susceptible to surface contamination.
Internal Medicine
2 questionsTabes dorsalis is seen in -
Meningitis with rash is seen in -
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 681: Tabes dorsalis is seen in -
- A. Tertiary syphilis (Correct Answer)
- B. Primary syphilis
- C. Latent syphilis
- D. Secondary syphilis
Explanation: ***Tertiary syphilis*** - **Tabes dorsalis** is a neurological manifestation of **tertiary syphilis**, characterized by demyelination and degeneration of the posterior columns of the spinal cord [1]. - This leads to symptoms such as **ataxia**, **loss of proprioception**, **lightning pains**, and **Argyll-Robertson pupils**. *Primary syphilis* - Characterized by the presence of a **chancre**, a painless ulcer, at the site of infection [1]. - This stage typically occurs 3-90 days after exposure and is not associated with neurological complications of tabes dorsalis. *Latent syphilis* - This is a period during which there are **no clinical signs or symptoms** of syphilis, although the infection persists. - It can be early or late, but it is not the stage where overt neurological complications like tabes dorsalis arise [1]. *Secondary syphilis* - This stage typically presents with a **generalized mucocutaneous rash**, **lymphadenopathy**, and **condylomata lata** [1]. - While it can involve various organ systems, it does not typically include the severe neurological degeneration seen in tabes dorsalis.
Question 682: Meningitis with rash is seen in -
- A. Neisseria meningitidis (Correct Answer)
- B. H. influenzae
- C. Strepto. agalactae
- D. Pneumococcus
Explanation: **Neisseria meningitidis** - **Meningococcal meningitis** is classically associated with an acute onset of fever, headache, stiff neck, and a characteristic **petechial or purpuric rash** [1]. - The rash is due to widespread **vasculitis** and disseminated intravascular coagulation (DIC) caused by the bacteria. *H. influenzae* - While *H. influenzae* type b (Hib) was a major cause of bacterial meningitis before vaccination, it typically does not cause a *rash*. - Meningitis caused by *H. influenzae* presents with fever, headache, stiff neck, and altered mental status without dermatological manifestations. *Strepto. agalactiae* - *Streptococcus agalactiae* (Group B Strep) is a common cause of meningitis in **neonates** and infants. - It usually presents with non-specific symptoms like fever, lethargy, and poor feeding, and a rash is not a typical feature of GBS meningitis. *Pneumococcus* - *Streptococcus pneumoniae* (Pneumococcus) is another leading cause of bacterial meningitis in adults and children [1]. - Symptoms include fever, headache, stiff neck, and altered mental status, but a cutaneous rash is not characteristic of pneumococcal meningitis [1].
Microbiology
2 questionsWhich of the following is an enrichment medium for cholera?
Which of the following statements is true regarding Diphyllobothrium?
NEET-PG 2012 - Microbiology NEET-PG Practice Questions and MCQs
Question 681: Which of the following is an enrichment medium for cholera?
- A. TCBS medium
- B. Cary-Blair medium
- C. Alkaline peptone water (Correct Answer)
- D. MacConkey agar
Explanation: ***Alkaline peptone water*** - This is a commonly used **enrichment broth** for *Vibrio cholerae* due to its **high pH (around 8.6)**, which selectively suppresses the growth of most other intestinal flora. - The alkaline environment provides a favorable condition for the rapid multiplication of *Vibrio cholerae* before subculturing onto selective media. *TCBS medium* - **Thiosulfate citrate bile salts sucrose (TCBS) agar** is a **selective and differential medium** used for the isolation of *Vibrio cholerae*, not an enrichment medium. - It differentiates *Vibrio cholerae* (yellow colonies) from most other *Vibrio* species (blue-green colonies) and inhibits the growth of most non-Vibrio bacteria. *Cary-Blair medium* - This is a **transport medium** designed to maintain the viability of enteric bacterial pathogens, including *Vibrio cholerae*, for extended periods at ambient temperatures. - It prevents overgrowth of commensals and helps preserve the pathogen's concentration, but it does not promote growth. *MacConkey agar* - **MacConkey agar** is a **selective and differential medium** primarily used for the isolation and differentiation of gram-negative enteric bacilli. - It is not specifically designed for *Vibrio cholerae* and its selective properties (bile salts and crystal violet) and differential properties (lactose fermentation) are less optimal for *Vibrio* isolation compared to specialized media.
Question 682: Which of the following statements is true regarding Diphyllobothrium?
- A. Humans are the only definitive host
- B. Vitamin B12 deficiency always occurs in infection
- C. Fish are definitive hosts
- D. The operculated egg is a diagnostic feature (Correct Answer)
Explanation: ***The operculated egg is a diagnostic feature*** - *Diphyllobothrium latum*, also known as the **fish tapeworm**, produces characteristic **operculated eggs** that are oval-shaped with an operculum (cap) at one end and a small knob at the other. - The presence of these **unembryonated eggs** in stool samples is the primary diagnostic method for diphyllobothriasis. *Humans are the only definitive host* - While humans are common definitive hosts, other **fish-eating mammals** such as bears, dogs, and cats can also serve as definitive hosts for *Diphyllobothrium latum*. - The definitive host is where the **adult worm resides** and reproduces sexually. *Vitamin B12 deficiency always occurs in infection* - **Vitamin B12 deficiency (megaloblastic anemia)** is a known complication of *Diphyllobothrium latum* infection, as the worm competes for B12 in the host's intestine. - However, it does **not occur in all infected individuals**; it is estimated to affect a significant minority, typically those with heavy worm burdens or prolonged infection, and can be influenced by dietary intake. *Fish are definitive hosts* - Fish (specifically freshwater fish like pike, perch, and salmon) act as **second intermediate hosts** for *Diphyllobothrium latum*, carrying the **plerocercoid larvae**. - **Humans and other fish-eating mammals** are the definitive hosts, where the plerocercoid larvae mature into adult tapeworms in the small intestine.