NEET-PG 2013 Practice Questions

Q: What anatomical structure is formed after the obliteration of the umbilical vein?

Round ligament of the liver (ligamentum teres). ***Round ligament of the liver (ligamentum teres)*** - The **umbilical vein** carries oxygenated blood from the placenta to the fetus during development [1]. - After birth, the umbilical vein obliterates and forms the **round ligament of the liver**, also known as the **ligamentum teres hepatis**. *Ligamentum venosum* - This structure is the obliterated remnant of the **ductus venosus**, which shunted blood from the umbilical vein to the inferior vena cava, bypassing the fetal liver [1]. - It is located in a fissure on the posterior surface of the liver, separate from the round ligament. *Ligamentum arteriosum* - This ligament is the remnant of the **ductus arteriosus**, a fetal blood vessel connecting the pulmonary artery to the aorta. - Its obliteration allows blood to flow through the lungs after birth. *Medial umbilical ligament* - This ligament is formed from the obliterated **umbilical arteries**, which carry deoxygenated blood from the fetus back to the placenta. - There are two medial umbilical ligaments, one from each umbilical artery.

Q: Transovarian transmission is seen in-

Rickettsial diseases. ***Rickettsial diseases*** - **Transovarian transmission** is a key mechanism for the maintenance and spread of **rickettsiae** in arthropod vectors. The bacteria can pass from an infected female arthropod (like a tick or mite) to her offspring via the eggs. - This ensures that the next generation of vectors is already infected and can transmit the disease, even without needing to acquire the pathogen from an infected vertebrate host. *Malaria* - Malaria is transmitted via the bite of an infected **Anopheles mosquito**, which acquires parasites from an infected human. - **Transovarian transmission** does not occur in malaria; mosquitoes are not born with the ability to transmit the parasite. *Filaria* - Filariasis is spread by various **mosquito vectors** (e.g., *Culex*, *Anopheles*, *Aedes*) or **black flies**, which acquire microfilariae from an infected host during a blood meal. - The parasite undergoes development within the insect, but **transovarian transmission** to the insect's offspring does not occur. *None of the options* - This option is incorrect because **rickettsial diseases** do exhibit transovarian transmission, making it a valid answer. - The phenomenon of passing pathogens directly from a female parent to her offspring via the egg is a specific mechanism seen in certain vector-borne diseases.

Q: Which of the following characteristics can be used to differentiate the rash of chickenpox from the rash of smallpox?

Pleomorphic. ***Pleomorphic*** - The rash of **chickenpox** is **pleomorphic**, meaning lesions at various stages of development (macules, papules, vesicles, scabs) are present simultaneously in the same body area. - In contrast, a **smallpox** rash is **monomorphic**, with all lesions in a given area appearing at the same stage of development. *Centrifugal* - A **centrifugal distribution** (lesions more concentrated on the face and extremities) is characteristic of **smallpox**. - **Chickenpox** typically has a **centripetal distribution**, with lesions more concentrated on the trunk. *Deep-seated* - **Smallpox** lesions are described as **deep-seated** and feel like "shot under the skin," often associated with significant scarring. - **Chickenpox** lesions are superficial and less likely to cause scarring unless secondarily infected. *Multilocular* - **Smallpox** vesicles and pustules are typically **multilocular**, meaning they have internal septations and do not collapse when punctured. - **Chickenpox** vesicles are unilocular, appearing as a single compartment, and collapse when punctured.

Q: What does testamentary capacity refer to?

Ability to make a valid will. ***Ability to make a valid will*** - **Testamentary capacity** specifically refers to the legal and mental competence required to create a legally binding **last will and testament**. - It ensures that the testator understands the nature of the act, the extent of their property, and the natural objects of their bounty (i.e., those who would reasonably expect to inherit). *Ability to create a will* - While related, this option is too broad; it doesn't emphasize the **legal validity** or the specific cognitive requirements involved in the process. - Simply "creating" a will may involve just writing it down, but it doesn't guarantee the **mental capacity** needed for it to be enforceable. *Ability to understand legal documents* - This is a general cognitive ability that is necessary but insufficient to define **testamentary capacity**. - A person might understand legal documents generally but lack the specific awareness of their assets or beneficiaries required for a valid will at a given time. *None of the options* - This is incorrect because the first option accurately describes **testamentary capacity**.

Q: In blast injury, which organ is most likely to be damaged first?

Tympanic membrane. ***Tympanic membrane*** - The **tympanic membrane** is the most sensitive organ to the pressure waves generated by a blast, often rupturing even with relatively low blast overpressures. - Its thin, delicate structure and direct exposure to external air pressure make it highly vulnerable to barotrauma. *Gastrointestinal tract* - While the **gastrointestinal tract** can be damaged by blast waves, especially air-filled organs, this typically occurs after the tympanic membrane is affected. - Damage often includes hemorrhage, perforation, and mesenteric injury. *Liver* - The **liver** is a solid organ and is less susceptible to initial blast injury compared to air-filled structures. - Damage to the liver usually results from secondary mechanisms like blunt trauma from displacement or impact against other structures. *Lung* - **Blast lung** is a serious injury characterized by pulmonary contusions, hemorrhage, and edema, but it generally requires higher blast overpressure than tympanic membrane rupture. - The air-filled nature of the lungs makes them susceptible, but the tympanic membrane almost always fails first.

Q: Glass vessels and syringes are best sterilised by -

Dry heat sterilization in a hot air oven. **Dry heat sterilization in a hot air oven** - **Dry heat sterilization** (160-180°C for 1-2 hours) is the **traditional and preferred method** for **glassware and glass syringes**. - **Hot air ovens** achieve sterilization by oxidative destruction and protein denaturation, leaving items completely **dry** and free from moisture. - **Advantages**: No corrosion, no rusting, items remain dry, ideal for **powders, oils, and glassware** that can withstand high temperatures. - **Note**: This question refers to **glass syringes** (historically used, now largely replaced by disposable plastic syringes which are pre-sterilized by radiation). *Steam sterilization in an autoclave* - **Autoclaving** uses **moist heat** (121°C at 15 psi for 15 minutes) and is highly effective for most medical instruments. - **Disadvantage for glassware**: Rapid temperature changes and steam exposure can cause **thermal shock, cracking, or etching** of delicate glassware. - Items emerge **wet** and require drying, which is undesirable for certain laboratory applications. - **Modern context**: Standard method for surgical instruments and heat-stable plastics. *Ethylene oxide sterilization* - **Ethylene oxide (ETO)** is a **low-temperature chemical sterilization** method (50-60°C) for heat-sensitive items. - Used for plastics, rubber, electronics, and endoscopes that cannot tolerate heat. - Requires **long exposure** (12-24 hours) and **aeration period** (up to 7 days) to remove toxic residues. - **Not preferred** for routine glassware sterilization when heat methods are suitable. *Radiation sterilization* - **Gamma radiation or electron beam** sterilization is used for **pre-packaged disposable medical devices**, pharmaceuticals, and plastic syringes. - Highly effective but **expensive** and requires specialized facilities. - Not practical for **routine laboratory glassware** sterilization in clinical or research settings.

Q: Which of the following statements about viruses is false?

Viruses are capable of independent motility.. ***Viruses are capable of independent motility.*** - Viruses are **acellular infectious agents** and lack the cellular machinery required for independent movement or motility. - They rely on host cell processes or environmental factors for their dissemination and entry into cells. *Viruses lack ribosomes.* - Viruses are **obligate intracellular parasites**; they lack ribosomes and other cellular organelles necessary for protein synthesis. - They hijack the host cell's ribosomes and metabolic machinery to replicate their genetic material and produce viral proteins. *Viruses lack mitochondria.* - Viruses lack mitochondria, as they are **not capable of generating their own ATP** through cellular respiration. - They depend on the host cell's energy-generating systems to provide the ATP required for their replication cycle. *Viruses contain nucleic acid.* - All viruses contain a **nucleic acid genome**, which can be either DNA or RNA. - This genetic material carries the instructions for viral replication and is enclosed within a protein coat called a **capsid**.

Q: Which of the following medications is known to cause peripheral neuropathy?

Vincristine. ***Vincristine*** - **Vincristine** is a **vinca alkaloid chemotherapeutic agent** that is **notorious** for causing **peripheral neuropathy** as its **dose-limiting toxicity**. - It interferes with **microtubule function** during mitosis, leading to **axonal damage** and predominantly **sensorimotor neuropathy**. - Peripheral neuropathy occurs in **virtually all patients** receiving vincristine and typically manifests as **distal paresthesias**, **loss of deep tendon reflexes**, and **motor weakness**. - This is the **most characteristic adverse effect** of vincristine. *Paclitaxel* - **Paclitaxel** is a **taxane chemotherapeutic agent** that also causes **peripheral neuropathy** as a significant adverse effect. - It stabilizes **microtubules**, preventing their depolymerization, leading to neurotoxicity. - While peripheral neuropathy is common with paclitaxel, it shares prominence with other major toxicities like **myelosuppression** and **hypersensitivity reactions**. *Sulfonamide* - **Sulfonamide antibiotics** are primarily associated with **hypersensitivity reactions**, **crystalluria**, **skin rashes**, and **hematologic abnormalities**. - Peripheral neuropathy is not a recognized or common adverse effect of sulfonamides. *Amiodarone* - **Amiodarone** is an **antiarrhythmic drug** with multiple adverse effects including **pulmonary fibrosis**, **thyroid dysfunction**, **corneal deposits**, and **hepatotoxicity**. - While rare cases of **peripheral neuropathy** have been reported, it is **not a characteristic or common adverse effect** of amiodarone.

Q: Which drug is primarily used in the treatment of breast cancer?

Tamoxifen. ***Tamoxifen*** - **Tamoxifen** is a **selective estrogen receptor modulator (SERM)** primarily used to treat and prevent **estrogen receptor (ER)-positive breast cancer**. - It works by blocking estrogen from binding to receptors in breast cancer cells, thereby inhibiting their growth. *Cyproterone* - **Cyproterone** is an **anti-androgen** and **progestogen** primarily used to treat conditions like **prostate cancer**, **acne**, and **hirsutism** in women. - Its main mechanism involves blocking androgen receptors and reducing androgen production, which is not the primary pathway for breast cancer. *Testosterone* - **Testosterone** is an **androgen** (male sex hormone) and is **not used** in the primary treatment of breast cancer. - In certain rare cases of severe metastatic breast cancer, androgens like high-dose testosterone have been historically used for palliation, but this is not standard therapy. *Chlorambucil* - **Chlorambucil** is an **alkylating agent** used primarily in the treatment of **chronic lymphocytic leukemia (CLL)** and certain **lymphomas**. - It works by interfering with DNA replication and transcription, but it is not a first-line or primary agent for breast cancer.

Question 1

What anatomical structure is formed after the obliteration of the umbilical vein?

Accepted Answer

Round ligament of the liver (ligamentum teres)

Answer

Ligamentum venosum

Answer

Ligamentum arteriosum

Answer

Medial umbilical ligament

Question 2

Transovarian transmission is seen in-

Accepted Answer

Rickettsial diseases

Answer

Malaria

Answer

Filaria

Answer

None of the options

Question 3

Which of the following characteristics can be used to differentiate the rash of chickenpox from the rash of smallpox?

Accepted Answer

Pleomorphic

Answer

Deep-seated

Answer

Centrifugal

Answer

Multilocular

Question 4

What does testamentary capacity refer to?

Accepted Answer

Ability to make a valid will

Answer

None of the options

Answer

Ability to create a will

Answer

Ability to understand legal documents

Question 5

In blast injury, which organ is most likely to be damaged first?

Accepted Answer

Tympanic membrane

Answer

Liver

Answer

Lung

Answer

Gastrointestinal tract

Question 6

Which of the following statements regarding resistance of penicillin in Staphylococcus aureus is false?

Accepted Answer

Hospital strains predominantly produce a unique type of penicillinase.

Answer

Methicillin resistance is due to alterations in penicillin-binding proteins (PBPs).

Answer

Penicillinase production is mediated by plasmids.

Answer

Penicillinase production can be transmitted by transduction.

Question 7

Glass vessels and syringes are best sterilised by -

Accepted Answer

Dry heat sterilization in a hot air oven

Answer

Steam sterilization in an autoclave

Answer

Ethylene oxide sterilization

Answer

Radiation sterilization

Question 8

Which of the following statements about viruses is false?

Accepted Answer

Viruses are capable of independent motility.

Answer

Viruses contain nucleic acid.

Answer

Viruses lack mitochondria.

Answer

Viruses lack ribosomes.

Question 9

Which of the following medications is known to cause peripheral neuropathy?

Accepted Answer

Vincristine

Answer

Sulfonamide

Answer

Amiodarone

Answer

Paclitaxel

Question 10

Which drug is primarily used in the treatment of breast cancer?

Accepted Answer

Tamoxifen

Answer

Cyproterone

Answer

Testosterone

Answer

Chlorambucil

NEET-PG 2013

Anatomy

Community Medicine

Forensic Medicine

Microbiology

Pharmacology