NEET-PG 2015 Practice Questions

Q: Which of the following acids is MOST commonly used as a reagent in medical laboratory analytical procedures?

Sulphuric acid is used in various laboratory processes.. ***Sulphuric acid*** is the most commonly used acid in medical laboratory analytical procedures. - **Sulfuric acid (H₂SO₄)** is a strong mineral acid with the **widest range of applications** in clinical and research laboratories - Used extensively as a **catalyst and reagent** in numerous analytical procedures including **protein digestion**, **Kjeldahl nitrogen estimation**, and **enzymatic assays** - Essential in **sample preparation** for heavy metal analysis and trace element detection - Utilized in **deproteinization** procedures and various **colorimetric assays** - Its strong **dehydrating properties** make it valuable in multiple biochemical protocols *Nitric acid* - **Nitric acid (HNO₃)** is primarily used for **acid digestion** of samples in trace element analysis - Strong **oxidizing agent** but has more **specialized applications** compared to sulfuric acid - More commonly used in **environmental and toxicology testing** than routine clinical biochemistry - Its highly **corrosive and oxidizing nature** limits its use in routine procedures *Carbolic acid* - **Carbolic acid (phenol/C₆H₅OH)** is technically not a mineral acid but a weak organic acid - Historically used as an **antiseptic and disinfectant** (Lister's antiseptic) - Modern laboratory use is **limited** to specific applications like **phenol-chloroform extraction** in molecular biology - Due to **toxicity concerns**, largely replaced by safer alternatives in routine disinfection *Oxalic acid* - **Oxalic acid (C₂H₂O₄)** is an organic dicarboxylic acid with **specialized applications** - Used in **decalcification of bone samples** for histopathology - Functions as a **reducing agent** in specific analytical procedures - Not a routine reagent in general medical laboratory practice compared to sulfuric acid

Q: What is the scientific name of the plant commonly known as Thorn apple?

Datura stramonium. ***Datura stramonium*** - This is the correct **scientific name** for the plant commonly known as **Thorn apple** or Jimsonweed. - *Datura stramonium* is known for its **anticholinergic** properties due to alkaloids like atropine, scopolamine, and hyoscyamine. *Nux vomica* - This plant is scientifically known as *Strychnos nux-vomica* and is a source of **strychnine** and brucine. - It is known for its **CNS stimulant** and convulsant effects, and is not referred to as Thorn apple. *Papaver somniferum* - This is the **opium poppy**, famous for producing **opium**, from which morphine, codeine, and heroin are derived. - Its common name is not Thorn apple, and its effects are primarily **analgesic** and sedative. *Cannabis sativa* - This plant is commonly known as **marijuana** or hemp, and it produces cannabinoids such as THC and CBD. - It is recognized for its **psychoactive** and medicinal properties, and is not related to Thorn apple.

Q: In the context of pharmacology, what is the term 'Mickey Finn' commonly associated with?

Chloral hydrate. ***Chloral hydrate*** - A "Mickey Finn" is a slang term for a drink **laced with a psychoactive drug or incapacitating agent** given to an unsuspecting person. - Historically, **chloral hydrate** was a common substance used for this purpose due to its rapid sedative-hypnotic effects. *Chloroform* - While chloroform is a potent anesthetic and sedative, it is primarily used as an **inhalant** and is not typically administered orally in drinks. - Ingesting chloroform in large quantities can be **fatal due to severe hepatotoxicity and neurotoxicity**. *Methyl alcohol* - **Methyl alcohol (methanol)** is highly toxic and causes severe metabolic acidosis, blindness, and death, even in small amounts. - It does not induce the quick, incapacitating sedative effects associated with a "Mickey Finn" but rather a **delayed, severe poisoning syndrome**. *Ethylene glycol* - **Ethylene glycol** is an antifreeze agent that is also highly toxic, causing kidney failure and metabolic derangements. - Similar to methanol, its effects are **delayed and severe**, not the immediate incapacitating sedation implied by the term "Mickey Finn."

Q: Which of the following can infect the ovary?

Mumps virus. ***Mumps virus*** - The mumps virus can cause **oophoritis** (inflammation of the ovary) in post-pubertal females, though it is less common than orchitis in males. - Oophoritis typically presents with **lower abdominal pain** and tenderness, often accompanied by fever and other mumps symptoms like parotitis. *Epstein-Barr Virus (EBV)* - While EBV causes **infectious mononucleosis** and is associated with various lymphomas and nasopharyngeal carcinoma, it is not a primary cause of direct ovarian infection. - EBV primarily targets **B lymphocytes** and epithelial cells, and ovarian involvement is not a typical manifestation. *Cytomegalovirus (CMV)* - CMV can cause a wide range of infections, particularly in **immunocompromised individuals** and neonates, leading to congenital abnormalities. - Although CMV can infect many organs, direct infection of the ovary leading to oophoritis is **extremely rare** and not a recognized clinical entity. *Measles virus* - The measles virus primarily causes a systemic infection characterized by a **maculopapular rash**, fever, cough, coryza, and conjunctivitis. - While it can lead to complications such as pneumonia or encephalitis, **ovarian involvement or oophoritis** is not a known or common complication of measles.

Q: Which immunoglobulin does Protein A of Staphylococcus aureus bind to?

IgG. ***IgG*** - **Protein A** of *Staphylococcus aureus* binds to the **Fc region** of IgG antibodies. - This binding mechanism helps *S. aureus* in **evading opsonization** and phagocytosis by interfering with the host immune response. *IgA* - IgA is primarily found in **mucosal secretions** and its primary role is in mucosal immunity. - Protein A does not preferentially bind to IgA; instead, some bacteria produce specific **IgA proteases** to cleave and inactivate IgA. *IgD* - IgD is found mostly on the surface of **B lymphocytes** and its main role is in B cell activation. - Protein A does not have a significant binding affinity for IgD. *IgE* - IgE is involved in **allergic reactions** and defense against parasites. - Protein A does not bind to IgE; binding to IgE is typically mediated by specific IgE receptors on mast cells and basophils.

Q: Proteus isolated from a patient of UTI will show which biochemical reaction.

Production of phenylpyruvic acid from phenylalanine. ***Production of phenylpyruvic acid from phenylalanine*** - *Proteus* species possess the enzyme **phenylalanine deaminase**, which deaminates phenylalanine to **phenylpyruvic acid**. - This reaction is a **key biochemical test** used to identify *Proteus*, *Providencia*, and *Morganella* species. *Hydrolysis of esculin in bile* - This reaction is characteristic of **Group D streptococci** and **enterococci**, not *Proteus* species. - The organism hydrolyzes **esculin** in the presence of bile, turning the agar black. *Sensitivity to colchicine* - **Colchicine** is an anti-inflammatory drug, not part of standard **biochemical identification tests** for bacteria. - This is not a recognized biochemical reaction used to identify *Proteus* or any bacterial species. *Sensitivity to bacitracin* - **Bacitracin sensitivity** is primarily used to differentiate **Group A streptococci** (e.g., *Streptococcus pyogenes*) from other beta-hemolytic streptococci. - It is an **antibiotic susceptibility test**, not a biochemical reaction characteristic of *Proteus* species.

Q: Best method of treatment for methyl alcohol poisoning is:

Ethyl alcohol. ***Ethyl alcohol*** - **Ethanol** (ethyl alcohol) acts as a competitive substrate for **alcohol dehydrogenase**, the enzyme responsible for metabolizing **methanol** into toxic metabolites like formaldehyde and formic acid. - By saturating alcohol dehydrogenase, ethanol prevents the formation of these toxic metabolites, allowing methanol to be excreted unchanged. - **Clinical note**: While **fomepizole** (4-methylpyrazole) is now the preferred first-line antidote when available, **ethanol** remains an effective and widely used alternative, especially in resource-limited settings. - **Administration**: IV ethanol is given to maintain blood ethanol concentration of 100-150 mg/dL. *Calcium gluconate* - **Calcium gluconate** is primarily used to treat **hypocalcemia**, ethylene glycol poisoning (for hypocalcemia), or hydrofluoric acid burns. - It has no role in the management of methyl alcohol poisoning as it does not interfere with the metabolism of methanol or its toxic byproducts. *Amphetamines* - **Amphetamines** are central nervous system stimulants used for conditions like ADHD and narcolepsy. - They have no therapeutic benefit or antidotal properties in the context of methanol poisoning. *1% Ammonia* - **Ammonia** is a strong base and is highly corrosive; it has no medical application as an antidote for methanol poisoning. - Administering ammonia would cause direct tissue damage and exacerbate patient harm due to its toxic and caustic properties.

Q: Which of the following is an opioid derived from morphine?

Heroin. ***Heroin*** - Heroin (**diacetylmorphine**) is synthesized from **morphine** through a simple acetylation process. - Morphine, an **opiate**, is naturally derived from the opium poppy. *Cocaine* - **Cocaine** is a powerful stimulant and local anesthetic derived from the **coca plant**. - It is a **naturally occurring alkaloid** but is not structurally or functionally related to opioids. *Dhatura* - **Dhatura** (Datura stramonium) contains **tropane alkaloids** like scopolamine and atropine, which have anticholinergic effects. - It is not an opioid and does not interact with opioid receptors. *Cannabis* - **Cannabis** (marijuana) contains **cannabinoids**, primarily THC, which act on cannabinoid receptors in the brain. - It is distinctly different from opioids in its chemical structure, mechanism of action, and effects.

Q: Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?

Curare. ***Curare*** - **Curare** is the traditional name for South American arrow poisons derived from plants, primarily *Chondrodendron tomentosum* and *Strychnos* species - It acts as a **competitive non-depolarizing neuromuscular blocking agent**, blocking nicotinic receptors at the neuromuscular junction - Causes **skeletal muscle paralysis** by competing with acetylcholine, leading to respiratory failure in prey - **Clinical relevance:** Tubocurarine (d-tubocurarine), derived from curare, was historically used as a muscle relaxant in surgery; modern derivatives include atracurium, vecuronium, and rocuronium *Opium* - **Opium** is derived from *Papaver somniferum* (opium poppy) and contains alkaloids like morphine and codeine - Acts on **opioid receptors** in the CNS to produce analgesia and sedation - Not used as an arrow poison by South American tribes; its effects are analgesic rather than paralytic *Cannabis* - **Cannabis** (*Cannabis sativa*) contains psychoactive compounds like THC (tetrahydrocannabinol) - Acts on **cannabinoid receptors** producing psychoactive and analgesic effects - Not used as an arrow poison; lacks the rapid paralytic action needed for hunting *Cyanide* - **Cyanide** inhibits cytochrome c oxidase, blocking cellular respiration and causing rapid cell death - While highly toxic, it is **not the traditional arrow poison** of South American indigenous tribes - Traditional arrow poisons like curare cause neuromuscular paralysis rather than cellular asphyxiation

Question 1

Which of the following acids is MOST commonly used as a reagent in medical laboratory analytical procedures?

Accepted Answer

Sulphuric acid is used in various laboratory processes.

Answer

Nitric acid is used in chemical analysis.

Answer

Carbolic acid is used as a disinfectant.

Answer

Oxalic acid is used in various laboratory applications.

Question 2

What is the scientific name of the plant commonly known as Thorn apple?

Accepted Answer

Datura stramonium

Answer

Nux vomica

Answer

Papaver somniferum

Answer

Cannabis sativa

Question 3

In the context of pharmacology, what is the term 'Mickey Finn' commonly associated with?

Accepted Answer

Chloral hydrate

Answer

Chloroform

Answer

Methyl alcohol

Answer

Ethylene glycol

Question 4

Which of the following can infect the ovary?

Accepted Answer

Mumps virus

Answer

Epstein-Barr Virus (EBV)

Answer

Cytomegalovirus (CMV)

Answer

Measles virus

Question 5

Which immunoglobulin does Protein A of Staphylococcus aureus bind to?

Accepted Answer

IgG

Answer

IgA

Answer

IgD

Answer

IgE

Question 6

Proteus isolated from a patient of UTI will show which biochemical reaction.

Accepted Answer

Production of phenylpyruvic acid from phenylalanine

Answer

Hydrolysis of esculin in bile

Answer

Sensitivity to colchicine

Answer

Sensitivity to bacitracin

Question 7

What is the key pathophysiological difference between acid and alkali injuries in terms of tissue necrosis?

Accepted Answer

Alkali injuries cause liquefactive necrosis

Answer

Acid injuries cause coagulative necrosis

Answer

Alkali injuries lead to deeper tissue damage

Answer

Acid injuries are less severe than alkali injuries

Question 8

Best method of treatment for methyl alcohol poisoning is:

Accepted Answer

Ethyl alcohol

Answer

Calcium gluconate

Answer

Amphetamines

Answer

1% Ammonia

Question 9

Which of the following is an opioid derived from morphine?

Accepted Answer

Heroin

Answer

Cocaine

Answer

Dhatura

Answer

Cannabis

Question 10

Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?

Accepted Answer

Curare

Answer

Opium

Answer

Cannabis

Answer

Cyanide

NEET-PG 2015

Biochemistry

Forensic Medicine

Microbiology

Pathology

Pharmacology