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: Pneumonic plague is spread by:

Droplet infection. ***Correct: Droplet infection*** - Pneumonic plague is a severe form of plague that affects the **lungs** and is transmitted through **respiratory droplets** expelled by an infected person or animal during coughing or sneezing. - This direct person-to-person transmission distinguishes it from other forms of plague. - It is the **only form of plague** that can spread directly from human to human without an animal or flea vector. *Incorrect: Bite of infected flea* - This is the primary mode of transmission for **bubonic plague**, where the bacterium *Yersinia pestis* is transmitted from rodents to humans via infected fleas. - While bubonic plague can progress to pneumonic plague, the initial transmission route for the pneumonic form itself is not flea bites. *Incorrect: Direct contact with infected tissue* - Direct contact with infected tissues or fluids can lead to **septicemic plague** or sometimes bubonic plague, especially in cases where there is a break in the skin. - This is not the typical or primary route for the spread of pneumonic plague, which is respiratory. *Incorrect: Ingestion of contaminated food* - Ingestion of contaminated food or water is a route for various **gastrointestinal infections** and diseases like salmonella or cholera. - It is not a known or common method for the transmission of any form of plague, including pneumonic plague.

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: Multiple drug resistance is transferred through -

Conjugation. ***Conjugation*** - Conjugation is a primary mechanism for the spread of **antibiotic resistance genes** among bacteria, including those responsible for multiple drug resistance. - It involves the direct transfer of **plasmids** (which often carry resistance genes) from one bacterial cell to another through a pilus. *Transduction* - Transduction is the process where bacteria acquire foreign DNA, including resistance genes, via a **bacteriophage (virus)**. - While it can transfer resistance, conjugation is a more common and clinically significant route for **multidrug resistance** spread. *Transformation* - Transformation involves the uptake of **naked DNA** from the environment by a bacterial cell. - While bacteria can acquire resistance genes this way, it is less efficient for widespread, rapid transfer of **multiple resistance traits** compared to conjugation. *Mutation* - Mutation refers to a change in the bacterial organism's own DNA, which can lead to the development of **drug resistance**. - However, mutation explains the *origin* of resistance in a single bacterium, not the *transfer* of resistance genes (especially multiple resistance) between different bacteria.

Q: Viral DNA is integrated into Bacterial DNA in:

Lysogenic cycle. ***Lysogenic cycle*** - In the **lysogenic cycle**, the **bacteriophage DNA integrates** into the host bacterial chromosome, becoming a **prophage**. - This integration allows the viral genome to be **replicated along with the host DNA** without immediately lysing the cell. *Bacterial transduction* - **Transduction** involves the transfer of **bacterial DNA** from one bacterium to another via a bacteriophage, not the integration of viral DNA into the host genome. - While phages are involved, the primary event is the accidental packaging and transfer of bacterial genes, not viral integration into the host for replication. *Bacterial transformation* - **Transformation** is the process where bacteria take up **naked DNA from their environment** and incorporate it into their own genome. - This DNA is typically from another bacterium or is artificially introduced, not viral DNA undergoing a natural integration process within the cell. *Bacterial conjugation* - **Conjugation** is the transfer of genetic material (usually a **plasmid**) between bacteria through direct cell-to-cell contact, mediated by a **pilus**. - This process involves the transfer of bacterial or plasmid DNA, not the integration of a viral genome into the host chromosome.

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

Pneumonic plague is spread by:

Accepted Answer

Droplet infection

Answer

Direct contact with infected tissue

Answer

Bite of infected flea

Answer

Ingestion of contaminated food

Question 3

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 4

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 5

Multiple drug resistance is transferred through -

Accepted Answer

Conjugation

Answer

Transduction

Answer

Transformation

Answer

Mutation

Question 6

Viral DNA is integrated into Bacterial DNA in:

Accepted Answer

Lysogenic cycle

Answer

Bacterial transduction

Answer

Bacterial transformation

Answer

Bacterial conjugation

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

Community Medicine

Forensic Medicine

Microbiology

Pathology

Pharmacology