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 strain of the Influenza A virus, not of human origin, has the highest pandemic potential?

H5N1. ***H5N1*** - The **H5N1 avian influenza virus** is widely considered to have high pandemic potential due to its ability to cause severe disease and high mortality in humans, despite limited human-to-human transmission. - It circulates extensively in **poultry populations**, providing ample opportunity for zoonotic spillover. *H1N1* - While H1N1 caused the **2009 swine flu pandemic**, the question specifies a strain "not of human origin" with high pandemic potential, and H1N1 is an avian-origin reassortant that adapted to humans. - Current circulating seasonal H1N1 strains already have some human immunity, reducing their pandemic potential. *H2N2* - The **H2N2 strain** caused the 1957 "Asian Flu" pandemic, and current human populations have some immunity due to previous exposure to related strains in circulation. - It is no longer circulating in humans and its pandemic potential is lower compared to novel highly pathogenic avian strains like H5N1. *H9N2* - **H9N2** is a low-pathogenic avian influenza virus that has caused sporadic human infections, primarily in agricultural workers. - While it has zoonotic potential, its infections in humans are typically mild and its capacity for sustained human-to-human transmission remains very limited, indicating lower pandemic potential than H5N1.

Q: What is a potential outcome of the integration of a viral genome into a host cell chromosome?

All of the options. ***All of the options*** - The insertion of a viral genome, known as a **provirus**, into the host chromosome can lead to a variety of sustained and complex interactions. - This integration can cause **long-term changes** in cell behavior, including altered gene expression and cell cycle regulation, which may manifest as any of the specified outcomes. *Malignancy* - Viral integration can interrupt or activate host genes, such as **oncogenes** or **tumor suppressor genes**, leading to uncontrolled cell proliferation and potential tumor formation. - An example is **human papillomavirus (HPV)** integrating into host cells, increasing the risk of cervical cancer. *Altered growth* - Integration can change the cell's normal growth patterns, either by promoting excessive division or by causing cell cycle arrest, impacting tissue development and function. - This can be due to the insertion of viral promoters or enhancers near growth-regulating genes. *Latency* - The integrated viral genome can remain dormant within the host chromosome without producing new viral particles for extended periods, a state known as **latency**. - During latency, the virus can be reactivated later to cause a productive infection, as seen with **herpesviruses**.

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

Q: From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?

Unripe capsule of the plant. ***Unripe capsule of the plant*** - The **latex** (or 'milk') containing **opioid alkaloids** like morphine and codeine is primarily harvested by incising the **unripe seed capsules** of the *Papaver somniferum* plant. - This milky sap is then collected and dried to produce **crude opium**. *Leaf of the plant* - The leaves of *Papaver somniferum* do not contain significant amounts of the latex and are not the primary source of **opium alkaloids**. - While some **alkaloids** might be present in trace amounts, they are not extracted commercially from the leaves. *Root of the plant* - The roots of the poppy plant are not known to exude latex or to be a significant source of medically relevant **opioid alkaloids**. - Their primary function is absorption of water and nutrients, and anchoring the plant. *Seeds of the plant* - While the dried seeds are used for culinary purposes (poppy seeds), they contain very low levels of **opioid alkaloids** compared to the latex. - The latex is produced within the **capsule** before the seeds fully mature.

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 strain of the Influenza A virus, not of human origin, has the highest pandemic potential?

Accepted Answer

H5N1

Answer

H1N1

Answer

H9N2

Answer

H2N2

Question 5

What is a potential outcome of the integration of a viral genome into a host cell chromosome?

Accepted Answer

All of the options

Answer

Altered growth

Answer

Malignancy

Answer

Latency

Question 6

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 7

Best method of treatment for methyl alcohol poisoning is:

Accepted Answer

Ethyl alcohol

Answer

Calcium gluconate

Answer

Amphetamines

Answer

1% Ammonia

Question 8

Which of the following is an opioid derived from morphine?

Accepted Answer

Heroin

Answer

Cocaine

Answer

Dhatura

Answer

Cannabis

Question 9

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

Question 10

From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?

Accepted Answer

Unripe capsule of the plant

Answer

Leaf of the plant

Answer

Root of the plant

Answer

Seeds of the plant

NEET-PG 2015

Biochemistry

Forensic Medicine

Microbiology

Pathology

Pharmacology