NEET-PG 2015 Practice Questions

Q: Which of the following statements about influenza infectivity is correct?

All of the options are correct.. ***All of the options are correct.*** - All statements provided accurately describe aspects of influenza infectivity and epidemiology. - The **communicable period**, the **primary source of infection**, and the potential for **subclinical cases** are all characteristic features of influenza. *Communicable period is 1 day before to 5-7 days after the onset of symptoms* - This statement is accurate, as influenza is transmissible **before symptom onset** and for several days afterward, which contributes to its rapid spread. - Peak viral shedding often occurs just before and in the first few days of symptomatic illness. - Adults typically shed virus from 1 day before to 5-7 days after symptom onset (can be longer in children and immunocompromised individuals). *The primary source of infection is a clinical case.* - This is correct, as **symptomatic individuals (clinical cases) are the PRIMARY source** of influenza virus transmission to others. - Respiratory droplets produced by coughing, sneezing, or talking from an infected person are the main mode of spread. - While subclinical cases can transmit, clinical cases with overt symptoms produce more respiratory droplets and are the major drivers of transmission. *There can be subclinical cases of influenza.* - This statement is correct; many individuals infected with influenza virus experience **mild or asymptomatic infections** (subclinical cases). - These subclinical cases can still transmit the virus, though typically to a lesser extent than symptomatic cases, further complicating control efforts.

Q: Human, animal, fomite or objects from which infective organism enters the host is called?

Source of infection. ***Source of infection*** - The **source of infection** refers to the person, animal, object, or substance from which an infectious agent passes immediately to a host. - This can include humans, animals, fomites, or contaminated objects that directly transmit the infectious organism. - This is the proximate source from which the agent enters the host. *Infective Reservoir* - An **infective reservoir** is the long-term habitat where an infectious agent normally lives, grows, and multiplies. - The reservoir can be human, animal, plant, soil, or inanimate matter where the agent is normally found. - While a reservoir can be a source, the source is specifically the immediate point from which transmission occurs. *Infective Carrier* - An **infective carrier** is an infected person or animal that harbors a specific infectious agent without showing clinical symptoms but can transmit it to others. - A carrier is a type of source (when transmission occurs from them), but the term "source" is broader, encompassing inanimate objects and fomites as well. *None of the above* - This option is incorrect because **Source of infection** accurately describes the concept presented in the question.

Q: Which of the following is seen in sarcoidosis

Increased calcium levels in the blood (Hypercalcemia). ***Increased calcium levels in the blood (Hypercalcemia)*** - In sarcoidosis, activated macrophages in granulomas produce **1-alpha hydroxylase**, which converts **25-hydroxyvitamin D to 1,25-dihydroxyvitamin D (calcitriol)** [1]. - This increased calcitriol leads to enhanced intestinal **calcium absorption** and occasional bone resorption, resulting in **hypercalcemia** [1]. *Decreased calcium levels in the blood (Hypocalcemia)* - **Hypocalcemia** is not characteristic of sarcoidosis; the disease typically involves dysregulated vitamin D metabolism causing elevated, not decreased, calcium [1]. - Conditions like **hypoparathyroidism** or **vitamin D deficiency** (unrelated to the sarcoidosis pathogenesis) would cause hypocalcemia. *Increased phosphate levels in the blood (Hyperphosphatemia)* - **Hyperphosphatemia** is not a feature of sarcoidosis. Calcium and phosphate levels often have an inverse relationship, so with hypercalcemia, phosphate levels tend to be normal or slightly decreased due to suppression of parathyroid hormone. - Hyperphosphatemia is more commonly associated with **renal failure** or certain **endocrine disorders**. *Decreased phosphate levels in the blood (Hypophosphatemia)* - While **hypophosphatemia** can occur in conditions with high vitamin D activity (as increased active vitamin D can promote renal phosphate excretion), it is not the primary or most notable electrolyte disturbance specifically linked to sarcoidosis. - **Hypercalcemia** is the more consistently observed electrolyte abnormality in sarcoidosis related to ectopic vitamin D production [1].

Q: Disruption of which of the following oropharyngeal commensals predisposes to candidiasis?

Streptococcus. ***Streptococcus*** - **Streptococcus** species, particularly *S. sanguinis* and *S. mitis*, are major commensals in the oral cavity that **inhibit the growth of *Candida albicans*** through competition for nutrients and production of antimicrobial substances. - Disruption of this normal **streptococcal flora**, often by broad-spectrum antibiotics, creates an environment where *Candida albicans* can proliferate, leading to candidiasis. *Staphylococcus* - **Staphylococcus** species are primarily skin and nasal commensals; while *S. aureus* can be found in the oral cavity, it is not a primary competitor against *Candida* in the same way as streptococci. - Their presence or absence is not typically a direct predisposing factor for oral candidiasis compared to the dominant streptococcal flora. *Lactobacillus* - **Lactobacillus** species are common in the gastrointestinal tract and vagina, where they maintain an acidic environment that inhibits pathogen growth; however, they are less dominant in the oropharynx as a defense against *Candida*. - While beneficial for overall host health, their disruption in the oral cavity does not typically precipitate candidiasis as directly as that of the **streptococcal flora**. *Hemophilus influenzae* - *Haemophilus influenzae* is a common inhabitant of the **upper respiratory tract** and can be an opportunistic pathogen, but it is not known to have a significant role in directly inhibiting *Candida* growth in the oropharynx. - Its presence or absence in the commensal flora in the oral cavity does not typically influence the development of candidiasis.

Q: Which of the following viruses is a member of the Herpesviridae family?

Herpes Simplex Virus. ***Herpes Simplex Virus*** - **Herpes Simplex Virus (HSV)** is the type species of the *Herpesviridae* family, which includes other common human pathogens such as **cytomegalovirus** and **Epstein-Barr virus**. - Members of this family are characterized by a **double-stranded DNA genome**, an icosahedral capsid, and an envelope, and they typically cause **latent infections**. *Variola* - **Variola virus** is a member of the *Poxviridae* family, known for causing **smallpox**, a historically devastating disease. - Unlike herpesviruses, poxviruses are **large and complex DNA viruses** that replicate entirely in the cytoplasm of infected cells. *Adenovirus* - **Adenovirus** belongs to the *Adenoviridae* family and is a **non-enveloped DNA virus** known for causing a variety of conditions, including respiratory infections and conjunctivitis. - Its structure and replication cycle differ significantly from the enveloped *Herpesviridae*. *HPV* - **HPV (Human Papillomavirus)** is a member of the *Papillomaviridae* family, which are small **non-enveloped DNA viruses** associated with warts and certain cancers. - It is distinct from herpesviruses in its genomic organization, capsid structure, and disease manifestations.

Q: Most common malignant tumor of the heart in adults

Cardiac Sarcoma. ***Cardiac Sarcoma*** - **Cardiac sarcomas** are the most common type of **primary malignant tumor** of the heart in adults, accounting for about 95% of primary malignant cardiac tumors. - **Angiosarcoma** is the most common subtype (approximately 33-50% of all cardiac sarcomas), typically originating from the **right atrium**. - These tumors are highly aggressive with rapid growth, early metastasis, and poor prognosis. - They commonly present with right-sided heart failure, pericardial effusion, or constitutional symptoms. *Rhabdomyoma* - **Rhabdomyomas** are the most common **primary cardiac tumors in infants and children** (60-80% of pediatric cardiac tumors), not adults. - These tumors are **benign** and strongly associated with tuberous sclerosis. - They often spontaneously regress after birth. *Lipoma* - **Lipomas** are **benign tumors** composed of mature adipocytes and account for about 10% of benign cardiac tumors. - They are typically asymptomatic and found incidentally. - They are not malignant and therefore not relevant to this question about malignant tumors. *Paraganglioma* - **Paragangliomas** (pheochromocytomas of the heart) are rare neuroendocrine tumors. - They are typically **benign** (though can be locally invasive) and may be hormonally active, causing catecholamine-related symptoms. - They represent less than 1% of cardiac tumors and are not the most common malignant cardiac tumor.

Q: Which of the following statements regarding Pertussis is INCORRECT?

Cerebellar ataxia is a known complication.. ***Cerebellar ataxia is a known complication.*** - **Cerebellar ataxia** is not a typical or known complication of pertussis. Complications usually involve the respiratory, neurological (e.g., seizures, encephalopathy due to hypoxia), and nutritional systems due to severe coughing. - While neurological complications can occur, **ataxia** specifically is not frequently sighted in the context of pertussis. *Some infections may be subclinical.* - Some individuals, especially those partially immunized or older, can experience **subclinical or atypical infections** with pertussis, often presenting as a mild cough. - This characteristic makes it difficult to control the spread of the disease as infected individuals may not be recognized. *The most infective stage is the catarrhal stage.* - The **catarrhal stage**, characterized by non-specific cold-like symptoms, is the most contagious phase because bacterial shedding is highest. - During this stage, symptoms are mild and often indistinguishable from a common cold, leading to widespread transmission before diagnosis. *The drug of choice is Erythromycin.* - **Erythromycin**, or other macrolides like azithromycin or clarithromycin, are the drugs of choice for treating pertussis. - These antibiotics are most effective when administered early in the **catarrhal stage** to reduce disease severity and prevent transmission.

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: Miracle fruit is used to change the taste from?

Sour to Sweet. ***Sour to Sweet*** - The **miracle fruit** (Synsepalum dulcificum) contains a glycoprotein called **miraculin**. - Miraculin binds to taste receptors on the tongue and modifies their perception, making **sour foods taste sweet**. *Sour to Bitter* - The primary effect of miracle fruit is to convert **sour tastes into sweet tastes**, not bitter ones. - No known natural compound consistently changes sour perception to bitter. *Bitter to Sweet* - While miraculin makes sour foods sweet, it does not typically convert **bitter tastes into sweet sensations**. - Bitter taste perception involves different receptor pathways that are not significantly altered by miraculin. *Salty to Sweet* - Miracle fruit primarily targets **sour taste receptors**. - It does not have a significant effect on altering the perception of **salty tastes to sweet**.

Q: What is the SI unit of luminous intensity?

Candela. ***Candela*** - The **candela (cd)** is the **SI base unit** used to measure **luminous intensity**. - **Luminous intensity** quantifies the power emitted by a light source in a particular direction per unit solid angle. *Lumen* - The **lumen (lm)** is the **SI derived unit** for **luminous flux**, which measures the total perceived power of light. - It describes the total amount of visible light emitted by a source in all directions, not its intensity in a specific direction. *Lux* - The **lux (lx)** is the **SI derived unit** for **illuminance**, which measures how much luminous flux is spread over a given area. - It indicates the perceived brightness of a surface, rather than the intensity of the light source itself. *Coulomb* - The **coulomb (C)** is the **SI derived unit** for **electric charge**. - It is completely unrelated to light or luminous intensity.

Question 1

Which of the following statements about influenza infectivity is correct?

Accepted Answer

All of the options are correct.

Answer

Communicable period is 1 day before to 5-7 days after the onset of symptoms

Answer

There can be subclinical cases of influenza.

Answer

The primary source of infection is a clinical case.

Question 2

Human, animal, fomite or objects from which infective organism enters the host is called?

Accepted Answer

Source of infection

Answer

Infective Reservoir

Answer

Infective Carrier

Answer

None of the above

Question 3

Which of the following is seen in sarcoidosis

Accepted Answer

Increased calcium levels in the blood (Hypercalcemia)

Answer

Decreased calcium levels in the blood (Hypocalcemia)

Answer

Increased phosphate levels in the blood (Hyperphosphatemia)

Answer

Decreased phosphate levels in the blood (Hypophosphatemia)

Question 4

Disruption of which of the following oropharyngeal commensals predisposes to candidiasis?

Accepted Answer

Streptococcus

Answer

Staphylococcus

Answer

Lactobacillus

Answer

Haemophilus influenzae

Question 5

Which of the following viruses is a member of the Herpesviridae family?

Accepted Answer

Herpes Simplex Virus

Answer

Variola

Answer

Adenovirus

Answer

HPV

Question 6

Most common malignant tumor of the heart in adults

Accepted Answer

Cardiac Sarcoma

Answer

Paraganglioma

Answer

Rhabdomyoma

Answer

Lipoma

Question 7

Which of the following statements regarding Pertussis is INCORRECT?

Accepted Answer

Cerebellar ataxia is a known complication.

Answer

The drug of choice is Erythromycin.

Answer

Some infections may be subclinical.

Answer

The most infective stage is the catarrhal stage.

Question 8

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 9

Miracle fruit is used to change the taste from?

Accepted Answer

Sour to Sweet

Answer

Sour to Bitter

Answer

Bitter to Sweet

Answer

Salty to Sweet

Question 10

What is the SI unit of luminous intensity?

Accepted Answer

Candela

Answer

Lumen

Answer

Lux

Answer

Coulomb

NEET-PG 2015

Community Medicine

Internal Medicine

Microbiology

Pathology

Pediatrics

Pharmacology

Physiology