Genetic and environmental risk factors US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Genetic and environmental risk factors. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Genetic and environmental risk factors US Medical PG Question 1: A researcher is investigating whether there is an association between the use of social media in teenagers and bipolar disorder. In order to study this potential relationship, she collects data from people who have bipolar disorder and matched controls without the disorder. She then asks how much on average these individuals used social media in the 3 years prior to their diagnosis. This continuous data is divided into 2 groups: those who used more than 2 hours per day and those who used less than 2 hours per day. She finds that out of 1000 subjects, 500 had bipolar disorder of which 300 used social media more than 2 hours per day. She also finds that 400 subjects who did not have the disorder also did not use social media more than 2 hours per day. Which of the following is the odds ratio for development of bipolar disorder after being exposed to more social media?
- A. 1.5
- B. 6 (Correct Answer)
- C. 0.17
- D. 0.67
Genetic and environmental risk factors Explanation: ***6***
- To calculate the odds ratio, we first construct a 2x2 table [1]:
- Bipolar Disorder (Cases): 500
- No Bipolar Disorder (Controls): 500 (1000 total subjects - 500 cases)
- Cases exposed to more social media (>2 hrs/day): 300
- Cases not exposed to more social media (≤2 hrs/day): 200 (500 - 300)
- Controls not exposed to more social media (≤2 hrs/day): 400
- Controls exposed to more social media (>2 hrs/day): 100 (500 - 400)
- The odds ratio (OR) is calculated as (odds of exposure in cases) / (odds of exposure in controls) = (300/200) / (100/400) = 1.5 / 0.25 = **6** [1].
*1.5*
- This value represents the **odds of exposure** (more than 2 hours of social media) in individuals with bipolar disorder (300 cases exposed / 200 cases unexposed = 1.5).
- It is not the odds ratio, which compares these odds to the odds of exposure in the control group.
*0.17*
- This value is close to the reciprocal of 6 (1/6 ≈ 0.166), suggesting a potential miscalculation or an inverted odds ratio.
- An odds ratio of 0.17 would imply a protective effect (lower odds of bipolar disorder with more social media), which is contrary to the calculation and typical interpretation in this context.
*0.67*
- This value is the reciprocal of 1.5 (1/1.5 ≈ 0.67) which represents the odds of *not* being exposed in cases (200/300).
- It does not represent the correct odds ratio, which compares the odds of exposure in cases to the odds of exposure in controls.
Genetic and environmental risk factors US Medical PG Question 2: A 52-year-old woman presents to her primary care physician for her annual checkup. She lost her job 6 months ago and since then she has been feeling worthless because nobody wants to hire her. She also says that she is finding it difficult to concentrate, which is exacerbated by the fact that she has lost interest in activities that she used to love such as doing puzzles and working in the garden. She says that she is sleeping over 10 hours every day because she says it is difficult to find the energy to get up in the morning. She denies having any thoughts about suicide. Which of the following neurotransmitter profiles would most likely be seen in this patient?
- A. Increased dopamine
- B. Decreased serotonin and norepinephrine (Correct Answer)
- C. Increased norepinephrine
- D. Decreased acetylcholine
- E. Decreased gamma-aminobutyric acid
Genetic and environmental risk factors Explanation: ***Decreased serotonin and norepinephrine***
- The patient's symptoms, including **worthlessness**, difficulty **concentrating**, loss of **interest (anhedonia)**, and **hypersomnia**, are classic for **major depressive disorder**.
- **Depression** is most commonly associated with a deficiency in **monoamine neurotransmitters**, particularly **serotonin** and **norepinephrine**, which play key roles in mood, sleep, appetite, and cognition.
*Increased dopamine*
- **Increased dopamine** activity is more often associated with conditions like **psychosis (e.g., schizophrenia)** or the manic phases of **bipolar disorder**, which are not indicated by the patient's symptoms.
- While dopamine is involved in reward and motivation, a primary increase is not the typical finding in major depression.
*Increased norepinephrine*
- An **increase in norepinephrine** is often seen in conditions like **anxiety disorders**, **panic attacks**, or **mania**, characterized by states of heightened arousal and vigilance.
- The patient's symptoms of **lethargy**, **hypersomnia**, and **lack of energy** point away from an overall increase in norepinephrine.
*Decreased acetylcholine*
- **Decreased acetylcholine** is primarily linked to cognitive deficits seen in conditions like **Alzheimer's disease**, affecting memory and learning.
- While depression can involve cognitive impairment, a primary deficit in acetylcholine is not the hallmark neurotransmitter change in major depressive disorder.
*Decreased gamma-aminobutyric acid*
- **Decreased GABA** (gamma-aminobutyric acid) is primarily associated with conditions of heightened excitability and anxiety, such as **anxiety disorders**, **insomnia**, and **seizure disorders**.
- The patient's presentation of **hypersomnia** and **low energy** is inconsistent with a primary GABA deficiency.
Genetic and environmental risk factors US Medical PG Question 3: A 45-year-old man presents with a hereditary condition affecting iron metabolism. The condition is caused by mutations in a gene that normally stimulates hepatic production of hepcidin, a hormone that downregulates iron absorption by inhibiting ferroportin (an iron transporter) on enterocytes. Due to this genetic defect, the patient has developed iron overload. He presents with skin hyperpigmentation, fatigue, joint pain, and diabetes mellitus. Laboratory studies show elevated serum ferritin and transferrin saturation. The patient is also developing early signs of cardiovascular complications from iron deposition. What would be the first cardiac manifestation in this patient?
- A. Preload: decreased, cardiac contractility: unchanged, afterload: increased (Correct Answer)
- B. Preload: decreased, cardiac contractility: decreased, afterload: decreased
- C. Preload: increased, cardiac contractility: increased, afterload: increased
- D. Preload: increased, cardiac contractility: decreased, afterload: increased
- E. Preload: increased, cardiac contractility: increased, afterload: decreased
Genetic and environmental risk factors Explanation: ***Preload: decreased, cardiac contractility: unchanged, afterload: increased***
- The first cardiac manifestation of **hereditary hemochromatosis** is typically **restrictive cardiomyopathy**, where iron deposition causes myocardial stiffening and impaired diastolic relaxation.
- In early restrictive disease, the stiff ventricle has **impaired filling**, leading to **reduced end-diastolic volume (decreased preload)** despite elevated filling pressures.
- **Systolic contractility remains initially unchanged** as the primary defect is diastolic dysfunction, not systolic failure.
- **Afterload is increased** due to compensatory peripheral vasoconstriction and reduced stroke volume triggering baroreceptor responses.
- This pattern reflects pure diastolic dysfunction with preserved systolic function (HFpEF pattern).
*Preload: decreased, cardiac contractility: decreased, afterload: decreased*
- While preload may be decreased, **reduced afterload** is inconsistent with restrictive cardiomyopathy, which typically shows compensatory vasoconstriction, not vasodilation.
- **Decreased contractility** occurs in later stages when iron toxicity directly damages myofibrils, progressing to dilated cardiomyopathy, but is not the initial presentation.
*Preload: increased, cardiac contractility: increased, afterload: increased*
- **Increased contractility** is not seen in iron-induced cardiac disease; iron deposition impairs, rather than enhances, myocardial function.
- This pattern would suggest a hyperdynamic state (e.g., sepsis, hyperthyroidism) which is unrelated to hemochromatosis.
*Preload: increased, cardiac contractility: decreased, afterload: increased*
- This combination describes **advanced or dilated cardiomyopathy** where the heart fails to pump effectively, causing volume overload and elevated preload.
- While this can occur in later stages of hemochromatosis, the **first cardiac manifestation** is restrictive (diastolic) dysfunction, not dilated (systolic) dysfunction.
- Decreased contractility develops after prolonged iron exposure damages contractile proteins.
*Preload: increased, cardiac contractility: increased, afterload: decreased*
- This pattern describes hyperdynamic circulation with reduced systemic vascular resistance, which does not occur in iron overload cardiomyopathy.
- Iron deposition causes myocardial stiffness and eventual contractile dysfunction, never enhanced contractility.
Genetic and environmental risk factors US Medical PG Question 4: A 36-year-old woman is brought to the emergency room by her husband for “weird behavior" for the past several weeks. He reports that her right arm has been moving uncontrollably in a writhing movement and that she has been especially irritable. She has a history of depression, which was diagnosed 4 years ago and is currently being treated with sertraline. She denies any recent fever, trauma, infections, travel, weakness, or sensory changes. She was adopted so is unsure of her family history. Which of the following is the most likely explanation for her symptoms?
- A. Frontotemporal lobe degeneration
- B. Presence of misfolded proteins in the brain
- C. Development of intracellular eosinophilic inclusions
- D. CAG triplet expansion on chromosome 4 (Correct Answer)
- E. GAA triplet expansion on chromosome 9
Genetic and environmental risk factors Explanation: ***CAG triplet expansion on chromosome 4***
- The patient's symptoms of **chorea** (uncontrolled writhing movements) and **irritability** (psychiatric changes) are classic manifestations of **Huntington's disease**.
- **Huntington's disease** is an autosomal dominant neurodegenerative disorder caused by a **CAG trinucleotide repeat expansion** on **chromosome 4** in the *HTT* gene.
*Frontotemporal lobe degeneration*
- **Frontotemporal dementia** typically presents with prominent behavioral changes (disinhibition, apathy) or language difficulties (aphasia), but **chorea** is not a characteristic feature.
- While psychiatric symptoms can occur, the specific motor dysfunction described points away from isolated frontotemporal degeneration.
*Presence of misfolded proteins in the brain*
- While **Huntington's disease** does involve misfolded huntingtin protein, this answer choice is too general and could apply to many neurodegenerative diseases like Alzheimer's (beta-amyloid, tau) or Parkinson's (alpha-synuclein).
- It does not specify the unique genetic basis directly responsible for the observed symptoms in this case.
*Development of intracellular eosinophilic inclusions*
- **Intracellular eosinophilic inclusions**, specifically **Lewy bodies**, are characteristic of **Parkinson's disease** and **Lewy body dementia**.
- These conditions primarily present with parkinsonism or dementia, not the prominent choreiform movements seen in this patient.
*GAA triplet expansion on chromosome 9*
- A **GAA triplet expansion on chromosome 9** is the genetic cause of **Friedreich's ataxia**, an autosomal recessive disorder.
- Friedreich's ataxia typically presents with progressive **ataxia**, dysarthria, and loss of proprioception, not chorea or prominent psychiatric changes like irritability.
Genetic and environmental risk factors US Medical PG Question 5: A 20-year-old college student comes to the physician because she has been extremely sad for the past 3 weeks and has to cry constantly. Three weeks ago, her boyfriend left her after they were together for 4 years. She has no appetite and has had a 2.3-kg (5.1-lb) weight loss. She has missed several classes because she could not stop crying or get out of bed. She thinks about her ex-boyfriend all the time. She says that she experienced similar symptoms for about 2 months after previous relationships ended. The patient is 158 cm (5 ft 2 in) tall and weighs 45 kg (100 lb); BMI is 18 kg/m2. Her temperature is 36.1°C (97°F), pulse is 65/min, and blood pressure is 110/60 mm Hg. Physical examination shows no abnormalities. On mental status examination she appears sad and cries easily. Which of the following is the most likely diagnosis?
- A. Bereavement
- B. Anorexia nervosa
- C. Major depressive disorder
- D. Acute stress disorder
- E. Adjustment disorder with depressed mood (Correct Answer)
Genetic and environmental risk factors Explanation: ***Adjustment disorder with depressed mood***
- This diagnosis is most likely as the patient’s symptoms (sadness, crying, loss of appetite, weight loss, difficulty getting out of bed) developed in response to an **identifiable stressor** (breakup with boyfriend) and occurred within **3 months** of its onset.
- The patient's history of similar, time-limited reactions to previous relationship endings supports an adjustment disorder pattern, where symptoms are **maladaptive** but resolve once the stressor is removed or a new level of adaptation is achieved, making it distinct from major depression due to its direct and timely link to a stressor.
*Bereavement*
- Bereavement involves the natural and expected emotional responses to the **death of a loved one**, which is not the case here as her boyfriend left her.
- While symptoms can overlap with depression, the precipitating event (death vs. breakup) distinguishes it from adjustment disorder.
*Anorexia nervosa*
- Anorexia nervosa is characterized by an **intense fear of gaining weight** or becoming fat, a distorted body image, and a persistent restriction of energy intake leading to a significantly low body weight.
- The patient's weight loss and poor appetite are attributed to her sadness and crying spells following a breakup, not primarily driven by a desire to be thin or body image preoccupation.
*Major depressive disorder*
- Major depressive disorder requires symptoms to be present for **at least 2 weeks** and significantly impair functioning, but the key differentiator here is the **clear and recent precipitating stressor** (breakup) and the history of similar, time-limited responses to past relationship endings.
- While the symptoms are severe, they are directly and clearly linked to the stressor, and the patient's pattern of response suggests an adjustment disorder rather than an endogenous depressive episode.
*Acute stress disorder*
- Acute stress disorder occurs in response to exposure to actual or threatened **death, serious injury, or sexual violence**, either directly or indirectly.
- The patient's stressor (a breakup) does not meet the criteria for a traumatic event required for acute stress disorder.
Genetic and environmental risk factors US Medical PG Question 6: A 42-year-old female presents to her primary care provider for an annual checkup. She reports feeling sad over the past few months for no apparent reason. She has lost interest in swimming, which she previously found enjoyable. Additionally, she has had trouble getting a full night’s sleep and has had trouble concentrating during the day. She has lost 15 pounds since her last visit one year prior. Which of the following sets of neurotransmitter levels is associated with this patient’s condition?
- A. Decreased acetylcholine, normal serotonin, normal dopamine
- B. Decreased norepinephrine, decreased serotonin, decreased dopamine (Correct Answer)
- C. Decreased GABA, decreased acetylcholine, increased dopamine
- D. Increased norepinephrine, decreased serotonin, decreased GABA
- E. Increased acetylcholine, increased serotonin, decreased dopamine
Genetic and environmental risk factors Explanation: ***Decreased norepinephrine, decreased serotonin, decreased dopamine***
- The patient's symptoms of **sadness**, loss of interest (**anhedonia**), **insomnia**, **difficulty concentrating**, and **weight loss** are classic for **major depressive disorder**.
- **Depression** is strongly associated with deficiencies in **monoamine neurotransmitters**: **norepinephrine**, **serotonin**, and **dopamine**.
*Decreased acetylcholine, normal serotonin, normal dopamine*
- While **acetylcholine** is involved in mood regulation, its isolated decrease with normal serotonin and dopamine levels is not characteristic of generalized depression.
- More prominent roles for **acetylcholine dysfunction** are seen in conditions like **Alzheimer's disease** or **myasthenia gravis**.
*Decreased GABA, decreased acetylcholine, increased dopamine*
- **Decreased GABA** is often associated with **anxiety disorders** and seizures, not the primary presentation of depression here.
- **Increased dopamine** is more characteristic of conditions like **schizophrenia** or **mania**, which contrasts with the patient's depressive symptoms.
*Increased norepinephrine, decreased serotonin, decreased GABA*
- **Increased norepinephrine** is typically associated with **anxiety**, **stress**, or sometimes **mania**, which is inconsistent with this patient's depressive state.
- While **decreased serotonin** is correct for depression, the combination with increased norepinephrine and decreased GABA does not fit the typical neurotransmitter profile.
*Increased acetylcholine, increased serotonin, decreased dopamine*
- **Increased acetylcholine** is generally not associated with the full spectrum of depressive symptoms described.
- **Increased serotonin** is often the goal of antidepressant treatments (SSRIs), making an endogenous increase unlikely to cause depression.
Genetic and environmental risk factors US Medical PG Question 7: A group of researchers studying the relationship between major depressive disorder and unprovoked seizures identified 36 patients via chart review who had been rehospitalized for unprovoked seizures following discharge from an inpatient psychiatric unit and 105 patients recently discharged from the same unit who did not experience unprovoked seizures. The results of the study show:
Unprovoked seizure No seizure
Major depressive disorder 20 35
No major depressive disorder 16 70
Based on this information, which of the following is the most appropriate measure of association between history of major depressive disorder (MDD) and unprovoked seizures?
- A. 1.95
- B. 2.5 (Correct Answer)
- C. 0.19
- D. 0.36
- E. 0.17
Genetic and environmental risk factors Explanation: ***2.5***
- This is a **case-control study** because it starts with individuals who have the outcome (unprovoked seizures) and individuals who do not, then looks back at their exposure (major depressive disorder).
- For a case-control study, the appropriate measure of association is the **odds ratio (OR)**, calculated as (a/c) / (b/d) = (ad) / (bc). In this case: a = 20 (MDD with seizure), b = 35 (MDD without seizure), c = 16 (no MDD with seizure), d = 70 (no MDD without seizure). So, OR = (20 * 70) / (35 * 16) = 1400 / 560 = 2.5.
*1.95*
- This value might be a calculation error or represent a different measure of association not applicable to this study design.
- The correct calculation for the odds ratio leads to 2.5.
*0.19*
- This value is likely a **relative risk** or **risk ratio**, which is used in cohort studies where risk is directly measured.
- In a case-control study, the **incidence of the outcome** cannot be directly determined, making relative risk an inappropriate measure.
*0.36*
- This value is not derived from the appropriate statistical calculation for the odds ratio in a case-control study.
- It might represent a **proportion** or a different type of risk calculation.
*0.17*
- This value is not the correct measure of association for a case-control study.
- It could be a miscalculation of a **prevalence ratio** or a different statistical metric.
Genetic and environmental risk factors US Medical PG Question 8: A 75-year-old Caucasian man presents to the emergency department with abdominal pain. The patient states he was at home eating dinner when he began to experience severe abdominal pain. The patient has a past medical history of diabetes, hypertension, and atherosclerosis. He lives at home alone, smokes cigarettes, and drinks 1 to 2 alcoholic drinks per day. The patient is given IV morphine and an ultrasound is obtained demonstrating a dilated abdominal aorta. The patient states that his father died of a similar finding and is concerned about his prognosis. Which of the following is the greatest risk factor for this patient's presentation?
- A. Male gender and age
- B. Caucasian race
- C. Cigarette smoking (Correct Answer)
- D. Family history
- E. Atherosclerosis
Genetic and environmental risk factors Explanation: ***Cigarette smoking***
- **Cigarette smoking** is the most significant modifiable risk factor for the development and expansion of **abdominal aortic aneurysms (AAAs)**, directly contributing to vascular inflammation and degradation.
- The patient's history of smoking suggests a strong causal link to his current presentation of a dilated aorta, which is highly indicative of an AAA.
*Male gender and age*
- While **male gender** and **advanced age (over 65)** are significant demographic risk factors for AAA, they are considered non-modifiable and less impactful than smoking in terms of risk magnitude.
- These factors increase predisposition but do not exert the same direct, damaging effect on the arterial wall as chronic smoking.
*Caucasian race*
- **Caucasian race** is a known demographic risk factor for AAA, with higher prevalence rates compared to other ethnic groups.
- However, this is a non-modifiable genetic predisposition and contributes less to the overall risk than modifiable lifestyle factors like smoking.
*Family history*
- A **family history** of AAA, as suggested by the patient's father having a similar condition, increases an individual's susceptibility.
- This is a significant non-modifiable risk factor, indicating genetic predisposition, but its overall impact on aneurysm formation and progression is typically less than that of active smoking.
*Atherosclerosis*
- **Atherosclerosis** is a strong associated condition with AAA, as both share common risk factors and pathology related to arterial wall degeneration.
- While atherosclerosis contributes to the overall vascular compromise, smoking specifically has a more direct and potent effect on promoting aneurysm formation and rupture independently.
Genetic and environmental risk factors US Medical PG Question 9: A 55-year-old woman presents to a primary care clinic for a physical evaluation. She works as a software engineer, travels frequently, is married with 2 kids, and drinks alcohol occasionally. She does not exercise regularly. She currently does not take any medications except for occasional ibuprofen or acetaminophen. She is currently undergoing menopause. Her initial vital signs reveal that her blood pressure is 140/95 mmHg and heart rate is 75/min. She weighs 65 kg (143 lb) and is 160 cm (63 in) tall. Her physical exam is unremarkable. A repeat measurement of her blood pressure is the same as before. Among various laboratory tests for hypertension evaluation, the physician requests fasting glucose and hemoglobin A1c levels. Which of the following is the greatest risk factor for type 2 diabetes mellitus?
- A. Menopause
- B. Occupation
- C. Age
- D. Body mass index (Correct Answer)
- E. Hypertension
Genetic and environmental risk factors Explanation: ***Body mass index***
- The patient's **BMI** is 25.4 kg/m², which falls into the **overweight** category (BMI 25-29.9 kg/m²). **Obesity** (BMI ≥ 30 kg/m²) and overweight status are significant and modifiable risk factors for **insulin resistance** and type 2 diabetes mellitus.
- Excess body fat, particularly **visceral fat**, leads to increased free fatty acid release and inflammation, impairing insulin signaling in target tissues.
*Menopause*
- While menopause can lead to changes in **body fat distribution** and increase the risk of metabolic syndrome components, it is not as strong a direct risk factor for type 2 diabetes as BMI.
- The hormonal shifts during menopause may contribute to **insulin resistance** but do not independently confer as high a risk as overweight or obesity.
*Occupation*
- The patient's occupation as a **software engineer** and frequent travel may contribute to a sedentary lifestyle, which is an indirect risk factor for obesity and diabetes. However, occupation itself is not a direct or primary biological risk factor.
- A sedentary lifestyle decreases **metabolic demand** and can lead to weight gain if not balanced with regular physical activity.
*Age*
- **Advancing age** is a known risk factor for type 2 diabetes due to a gradual decline in pancreatic beta-cell function and increased insulin resistance over time.
- While the patient's age (55) is a risk factor, her elevated **BMI** represents a more immediate and modifiable risk for developing the disease.
*Hypertension*
- **Hypertension** is often a comorbidity of type 2 diabetes and part of the **metabolic syndrome**, but it is generally considered a consequence or co-existing condition rather than the primary risk factor for the development of diabetes itself.
- Both hypertension and type 2 diabetes share common pathophysiological mechanisms such as **insulin resistance** and inflammation.
Genetic and environmental risk factors US Medical PG Question 10: A 68-year-old man with type 2 diabetes mellitus comes to the physician because of a 5-month history of episodic palpitations, dizziness, and fatigue. His pulse is 134/min and irregularly irregular, and his blood pressure is 165/92 mm Hg. An ECG shows a narrow complex tachycardia with absent P waves. He is prescribed a drug that decreases the long-term risk of thromboembolic complications by inhibiting the extrinsic pathway of the coagulation cascade. The expected beneficial effect of this drug is most likely due to which of the following actions?
- A. Inhibit the reduction of vitamin K (Correct Answer)
- B. Activate gamma-glutamyl carboxylase
- C. Inhibit the phosphorylation of glutamate on the factor II precursor
- D. Activate factor VII calcium-binding sites
- E. Inhibit the absorption of vitamin K
Genetic and environmental risk factors Explanation: ***Inhibit the reduction of vitamin K***
- The patient's symptoms and ECG findings (irregularly irregular pulse, absent P waves, narrow complex tachycardia) are consistent with **atrial fibrillation**, which carries a high risk of **thromboembolic complications**.
- The drug described, acting on the **extrinsic pathway** and reducing thromboembolic risk, is most likely **warfarin**, a **vitamin K antagonist** that inhibits the reduction (regeneration) of vitamin K, thus impairing the synthesis of coagulation factors II, VII, IX, and X.
*Activate gamma-glutamyl carboxylase*
- **Gamma-glutamyl carboxylase** is an enzyme that requires reduced vitamin K as a cofactor.
- Warfarin's action is to **inhibit** the enzyme that *reduces* vitamin K, thereby *reducing* the activity of gamma-glutamyl carboxylase, not activating it.
*Inhibit the phosphorylation of glutamate on the factor II precursor*
- The modification of glutamate residues on coagulation factors is through **gamma-carboxylation**, not phosphorylation.
- Warfarin inhibits the **gamma-carboxylation** of factors II, VII, IX, and X, not their phosphorylation.
*Activate factor VII calcium-binding sites*
- Factor VII, like other vitamin K-dependent factors, requires **gamma-carboxylation** for calcium binding, which is essential for its activation and function.
- Warfarin **inhibits** this carboxylation, thereby impairing calcium binding and the activation of these factors, rather than activating their calcium-binding sites.
*Inhibit the absorption of vitamin K*
- While vitamin K absorption can be affected by certain conditions or drugs (e.g., malabsorption syndromes, broad-spectrum antibiotics), warfarin's primary mechanism of action is **post-absorption**, targeting the **epoxide reductase enzyme** involved in vitamin K recycling, not its intestinal absorption.
More Genetic and environmental risk factors US Medical PG questions available in the OnCourse app. Practice MCQs, flashcards, and get detailed explanations.
