NEET-PG 2022 Practice Questions

Q: What is the term for a single mutation in a nucleotide base pair that results in a termination codon?

Nonsense mutation. ***Nonsense mutation*** - A **nonsense mutation** occurs when a single nucleotide base pair change leads to the formation of a **premature stop codon**, which results in a truncated and often non-functional protein. - The term "nonsense" refers to the fact that the new codon signals an early termination of protein synthesis. *Missense mutation* - A **missense mutation** involves a single nucleotide change that results in a codon coding for a **different amino acid**, potentially altering protein function but not necessarily terminating it. - This type of mutation can have varying effects on protein function, from benign to severe, depending on the amino acid substitution. *Termination mutation* - While a nonsense mutation does result in **premature termination**, "termination mutation" is not the standard or most precise scientific term used to describe this specific type of genetic alteration. - The more accurate and widely accepted terminology is **nonsense mutation** for a change leading to a stop codon. *Silent mutation* - A **silent mutation** is a type of point mutation that changes a single nucleotide, but does not change the amino acid sequence of the protein due to the **degeneracy of the genetic code**. - These mutations have **no observable effect** on the organism's phenotype as the protein produced remains unchanged.

Q: The electron transport chain is a series of redox reactions that result in ATP synthesis. Which of the following is a cytochrome complex IV inhibitor?

Cyanide. ***Cyanide*** - **Cyanide** is a potent inhibitor of **cytochrome c oxidase (Complex IV)** in the electron transport chain, binding to the ferric iron (Fe3+) in the heme group of the enzyme. - This binding prevents the transfer of electrons to **oxygen**, thereby halting cellular respiration and ATP production. *Carbon dioxide* - **Carbon dioxide** is a metabolic waste product and a component of the **bicarbonate buffer system**, but it does not directly inhibit cytochrome complex IV. - While high levels can affect physiological pH and enzyme function, its primary role is not as an electron transport chain inhibitor. *Oligomycin* - **Oligomycin** inhibits **ATP synthase (Complex V)** by binding to its Fo subunit, which blocks the flow of protons through the ATP synthase channel. - This prevents the synthesis of ATP but does not directly affect the electron transfer steps of cytochrome complex IV. *Ouabain* - **Ouabain** is a cardiac glycoside that inhibits the **Na+/K+-ATPase pump** in the cell membrane. - It does not have any direct inhibitory effect on the components of the electron transport chain, including cytochrome complex IV.

Q: Based on healthcare utility values and life expectancy, which of the following measures can be calculated? Consider a scenario where the average life expectancy for a woman in Japan is 87 years, and there is an increase in life expectancy due to healthcare advancements.

QALY. ***QALY*** - **Quality-Adjusted Life Years (QALYs)** combine the length of life with the **quality of life** lived, taking into account healthcare utility values (e.g., from 0 for dead to 1 for perfect health). - An increase in life expectancy due to healthcare advancements, coupled with assumed utility values, directly enables the calculation of QALYs gained or lost. *HALE* - **Health-Adjusted Life Expectancy (HALE)** is a measure of the average number of years that a person can expect to live in "**full health**" by adjusting for years lived in less than full health due to disease or injury. - While it incorporates health status, it specifically focuses on time lived in full health rather than the utility-weighted quality of life over the entire lifespan as QALYs do. *DALY* - **Disability-Adjusted Life Years (DALYs)** measure the total number of healthy years lost due to disease, disability, or premature death. - DALYs are a measure of disease burden, quantifying years lost, whereas QALYs are a measure of health gains or health states. *DFLE* - **Disability-Free Life Expectancy (DFLE)** measures the expected number of years an individual will live without disability. - While it considers the absence of disability, it does not incorporate the concept of "utility values" or varying degrees of health-related quality of life beyond a binary disabled/non-disabled state, as QALYs do.

Q: A militant presents with rashes all over his body sparing the palms and soles. On examination, he was febrile and lice were noted. Which of the following is responsible for his condition?

Rickettsia prowazekii. ***Rickettsia prowazekii*** - This bacterium is the causative agent of **epidemic typhus**, which is transmitted by the **body louse** (Pediculus humanus corporis), consistent with the presence of lice. - The characteristic rash of epidemic typhus **spares the palms and soles** and often begins on the trunk, spreading centrifugally. *Rickettsia typhi* - This organism causes **murine typhus**, which is transmitted by **fleas**, particularly those found on rodents. - While it can cause a rash that typically spares the palms and soles, the transmission vector and typical setting (exposure to rodents) do not fit the clinical scenario as well as **body lice**. *Rickettsia akari* - This bacterium causes **rickettsialpox**, transmitted by **mites**. - The rash of rickettsialpox is typically papulovesicular, and a characteristic **eschar** (or black scab) is usually present at the site of the mite bite, which is not mentioned in the case. *Rickettsia conorii* - This organism causes **Mediterranean spotted fever** (also known as Boutonneuse fever), transmitted by **ticks**. - A distinguishing feature of this infection is the presence of a **tache noire** (eschar) at the site of the tick bite, which is absent in the patient's presentation.

Q: A child presents with recurrent chest infections and abdominal pain. There is a history of 1 blood transfusion in the past. On examination, he had icterus and mild splenomegaly. Electrophoresis shows increased HbA2, HbF, and S spike. What is the likely diagnosis?

Sickle Beta Thalassemia. ***Sickle Beta Thalassemia*** - The combination of **sickle cell disease manifestations** (recurrent chest infections, abdominal pain, icterus, splenomegaly) with **electrophoresis showing increased HbA2, elevated HbF, and S spike** is diagnostic of **Sickle Beta Thalassemia**. - **Increased HbA2 (>3.5%)** is the key distinguishing feature that differentiates this from pure sickle cell disease. It indicates co-inheritance of a **beta-thalassemia gene** along with the **sickle cell gene**. - Clinical presentation is similar to sickle cell disease with **vaso-occlusive crises**, **acute chest syndrome**, hemolytic anemia, and organomegaly. - The severity depends on the type: S/β⁰-thalassemia (no HbA production) is clinically more severe and similar to SS disease, while S/β⁺-thalassemia (reduced HbA) tends to be milder. *Sickle cell disease* - Pure sickle cell disease (HbSS) presents with similar clinical features: recurrent chest infections, abdominal pain, hemolysis, and splenomegaly. - However, electrophoresis would show **normal or only slightly elevated HbA2 (2-3%)**, not the increased HbA2 mentioned in this case. - The presence of significantly increased HbA2 rules out pure sickle cell disease. *HbC disease* - Patients with HbC disease typically have **mild chronic hemolytic anemia** and **splenomegaly** but usually lack severe vaso-occlusive crises. - Electrophoresis would show primarily **HbC**, not an S spike. - The clinical picture is much milder than described in this case. *Aplastic anemia* - Characterized by **pancytopenia** due to bone marrow failure, leading to fatigue, infections, and bleeding tendency. - Does not involve hemolysis, icterus, or abnormal hemoglobin variants on electrophoresis. - The electrophoresis findings completely exclude this diagnosis.

Q: Which of the following is most likely to be seen due to the rupture of a saccular aneurysm?

Subarachnoid hemorrhage. ***Subarachnoid hemorrhage*** - A **saccular aneurysm** (often a **berry aneurysm**) commonly ruptures into the **subarachnoid space**, causing bleeding around the brain [2]. - This leads to a sudden onset of a "thunderclap headache," **meningeal irritation**, and neurological deficits [1]. *Subdural hemorrhage* - A **subdural hemorrhage** is typically caused by the tearing of **bridging veins** between the dura and arachnoid mater, often due to **trauma** [3]. - While it can occur, it is a less common direct consequence of saccular aneurysm rupture compared to subarachnoid hemorrhage. *Intracerebral hemorrhage* - An **intracerebral hemorrhage** involves bleeding directly into the brain parenchyma, most often due to **hypertension** or **amyloid angiopathy**. - Although a ruptured aneurysm can rarely extend into the brain tissue, the primary initial bleeding is usually into the subarachnspace [4]. *Hydrocephalus* - **Hydrocephalus** can be a *complication* of a subarachnoid hemorrhage, resulting from impaired CSF reabsorption or obstruction of CSF flow due to blood clots. - However, it is not the *initial event* caused directly by the rupture of a saccular aneurysm [4].

Q: A male child presented with arthralgia and abdominal pain. On examination, there was palpable purpura over the lower limbs. There is a past history of upper respiratory tract infection prior to the onset of presenting symptoms. Which of the following is the treatment for this condition?

Glucocorticoids. ***Glucocorticoids*** - The constellation of **arthralgia**, **abdominal pain**, and **palpable purpura** following an **upper respiratory tract infection** in a child is highly suggestive of **Henoch-Schönlein purpura (HSP)**, now known as **IgA vasculitis**. - **Glucocorticoids** are indicated in HSP for severe symptoms like significant abdominal pain, gastrointestinal bleeding, or painful arthralgia, all of which this patient demonstrates. - While HSP often resolves spontaneously with supportive care, this patient's presentation with both arthralgia and abdominal pain warrants glucocorticoid therapy. *Azathioprine* - **Azathioprine** is an immunosuppressant typically used for conditions like rheumatoid arthritis, IBD, or organ transplant rejection. - It is not a first-line treatment for the acute management of **IgA vasculitis**, which typically responds to supportive care or short courses of steroids for severe symptoms. *Methotrexate* - **Methotrexate** is a disease-modifying antirheumatic drug (DMARD) used in conditions such as rheumatoid arthritis, psoriasis, and certain cancers. - It does not have a role in the acute treatment of uncomplicated **IgA vasculitis** based on the described symptoms. *Cyclosporine* - **Cyclosporine** is a potent immunosuppressant used in severe autoimmune conditions or to prevent organ rejection. - While it may be considered in very severe, refractory cases of **IgA vasculitis** with significant renal involvement, it is not the initial treatment for the symptoms presented.

Q: A woman, who is 4 days postpartum, presented with tearfulness, mood swings, and occasional insomnia. What is the likely diagnosis?

Postpartum blues. ***Postpartum blues*** - This condition presents with mild, transient symptoms like **tearfulness**, **mood swings**, and **insomnia** typically peaking around **4-5 days postpartum** and resolving within two weeks. - It is a very common, self-limiting condition impacting up to 80% of new mothers, attributed to drastic **hormonal shifts** post-delivery. *Postpartum depression* - Symptoms are similar to postpartum blues but are more **severe**, last longer (typically **beyond two weeks**), and significantly impair functioning. - It often includes feelings of **hopelessness**, pervasive sadness, loss of pleasure, and sometimes thoughts of harming oneself or the baby. *Postpartum psychosis* - This is a severe psychiatric emergency characterized by **hallucinations**, delusions, disorganized thinking, and bizarre behavior, usually within the first 2-3 weeks postpartum. - It is a rare condition requiring **urgent medical intervention** due to the high risk of harm to mother and baby. *Postpartum anxiety* - While anxiety can co-occur with postpartum blues or depression, primary postpartum anxiety specifically involves excessive and **uncontrollable worry** or fear, often about the baby's health or safety. - It does not typically present with the prominent **tearfulness** and **mood swings** characteristic of blues or depression.

Q: A 59-year-old lady presents with a progressive, painless lump in the breast. What is the cause of the skin change associated with breast cancer?

Infiltration of subdermal lymphatics. ***Infiltration of subdermal lymphatics*** - The skin change described often refers to **peau d'orange**, which is caused by the **blockage of superficial lymphatic vessels** by tumor cells [1]. - This lymphatic obstruction leads to **edema** and dimpling of the skin, resembling an orange peel [1]. *Infiltration of the lactiferous duct* - While cancer can arise in or infiltrate lactiferous ducts, this primarily causes symptoms like **nipple discharge**, inversion, or a palpable mass. - It does not directly explain the specific **skin dimpling** or **peau d'orange** appearance. *Involvement of Cooper's ligament* - Involvement of **Cooper's ligaments** (suspensory ligaments of the breast) can cause skin dimpling or retraction [1]. - However, the image depicts widespread **peau d'orange**, which is more commonly associated with lymphatic involvement than direct ligamentous retraction [1]. *Spread of the tumor to the anterior chest wall* - Tumor extension to the **anterior chest wall** signifies advanced disease and can cause **fixation of the breast** to underlying structures or skin ulceration [2]. - This typically results in **immobility of the breast** or an ulcerated lesion, not the widespread edematous and dimpled appearance of **peau d'orange**. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 453-454. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 456-457.

Q: Identify the most common site of an intraperitoneal abscess.

Pelvis (Pouch of Douglas). ***Pelvis (Pouch of Douglas)*** - The **Pouch of Douglas** (rectouterine or rectovesical pouch) is the **most common site** for intraperitoneal abscesses. - It is the **most dependent (lowest) part** of the peritoneal cavity in both upright and supine positions, allowing gravity to facilitate collection of infected fluid. - Commonly results from **perforated appendicitis**, **diverticulitis**, **gynecological infections** (PID, tubo-ovarian abscess), or any source of peritoneal contamination where infected material flows downward. - **Clinical significance**: Pelvic abscesses can be drained via transrectal or transvaginal approaches, making them accessible for percutaneous drainage. *Subhepatic* - The **subhepatic space** (Morison's pouch on the right) is a **common but not the most common** site for intraperitoneal abscesses. - More specifically associated with **cholecystitis**, **perforated duodenal ulcers**, or hepatobiliary surgery complications. - While dependent in the supine position, it is less dependent than the pelvis in the upright position. *Suprahepatic* - Abscesses in the **suprahepatic space** are relatively uncommon. - May occur from direct extension of liver abscesses or as complications of upper abdominal surgery. - The presence of peritoneal attachments limits widespread fluid collection in this area. *Left subphrenic space* - The **left subphrenic space** is less commonly involved than the pelvis or right subphrenic spaces. - Typically arises from complications of **splenic injury**, **pancreatitis**, **gastric perforations**, or post-splenectomy infections.

Question 1

What is the term for a single mutation in a nucleotide base pair that results in a termination codon?

Accepted Answer

Nonsense mutation

Answer

Missense mutation

Answer

Termination mutation

Answer

Silent mutation

Question 2

The electron transport chain is a series of redox reactions that result in ATP synthesis. Which of the following is a cytochrome complex IV inhibitor?

Accepted Answer

Cyanide

Answer

Carbon dioxide

Answer

Oligomycin

Answer

Ouabain

Question 3

Based on healthcare utility values and life expectancy, which of the following measures can be calculated? Consider a scenario where the average life expectancy for a woman in Japan is 87 years, and there is an increase in life expectancy due to healthcare advancements.

Accepted Answer

QALY

Answer

HALE

Answer

DALY

Answer

DFLE

Question 4

A militant presents with rashes all over his body sparing the palms and soles. On examination, he was febrile and lice were noted. Which of the following is responsible for his condition?

Accepted Answer

Rickettsia prowazekii

Answer

Rickettsia typhi

Answer

Rickettsia akari

Answer

Rickettsia conorii

Question 5

A child presents with recurrent chest infections and abdominal pain. There is a history of 1    blood transfusion in the past. On examination, he had icterus and mild splenomegaly.    Electrophoresis shows increased HbA2, HbF, and S spike. What is the likely diagnosis?

Accepted Answer

Sickle Beta Thalassemia

Answer

HbC disease

Answer

Sickle cell disease

Answer

Aplastic anemia

Question 6

Which of the following is most likely to be seen due to the rupture of a saccular aneurysm?

Accepted Answer

Subarachnoid hemorrhage

Answer

Subdural hemorrhage

Answer

Intracerebral hemorrhage

Answer

Hydrocephalus

Question 7

A male child presented with arthralgia and abdominal pain. On examination, there was palpable purpura over the lower limbs. There is a past history of upper respiratory tract infection prior to the onset of presenting symptoms. Which of the following is the treatment for this condition?

Accepted Answer

Glucocorticoids

Answer

Azathioprine

Answer

Methotrexate

Answer

Cyclosporine

Question 8

A woman, who is 4 days postpartum, presented with tearfulness, mood swings, and occasional insomnia. What is the likely diagnosis?

Accepted Answer

Postpartum blues

Answer

Postpartum depression

Answer

Postpartum psychosis

Answer

Postpartum anxiety

Question 9

A 59-year-old lady presents with a progressive, painless lump in the breast. What is the cause of the skin change associated with breast cancer?

Accepted Answer

Infiltration of subdermal lymphatics

Answer

Infiltration of the lactiferous duct

Answer

Involvement of Cooper’s ligament

Answer

Spread of the tumor to the anterior chest wall

Question 10

Identify the most common site of an intraperitoneal abscess.

Accepted Answer

Pelvis (Pouch of Douglas)

Answer

Suprahepatic

Answer

Left subphrenic space

Answer

Subhepatic

NEET-PG 2022

Biochemistry

Community Medicine

Microbiology

Pathology

Pediatrics

Psychiatry

Surgery