Biochemistry
1 questionsWhich of the following is NOT present in DNA?
NEET-PG 2013 - Biochemistry NEET-PG Practice Questions and MCQs
Question 21: Which of the following is NOT present in DNA?
- A. Uracil (Correct Answer)
- B. Thymine
- C. Adenine
- D. Cytosine
Explanation: ***Uracil*** - **Uracil** is a pyrimidine nitrogenous base that replaces **thymine** in RNA, meaning it is not found in the structure of DNA. - In RNA, uracil pairs with **adenine** through two hydrogen bonds. *Thymine* - **Thymine** is a pyrimidine found in DNA, where it pairs with **adenine**. - It is replaced by **uracil** in RNA. *Cytosine* - **Cytosine** is a pyrimidine that is a fundamental component of both **DNA** and **RNA**. - In DNA, cytosine pairs with **guanine**. *Adenine* - **Adenine** is a purine that is a fundamental component of both **DNA** and **RNA**. - In DNA, adenine pairs with **thymine**, and in RNA, it pairs with **uracil**.
Community Medicine
1 questionsScreening for colorectal cancer is recommended when?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 21: Screening for colorectal cancer is recommended when?
- A. The condition has a low case fatality rate.
- B. Diagnostic tools are not available.
- C. There is no effective treatment available.
- D. Early diagnosis can change the disease course due to effective treatment. (Correct Answer)
Explanation: ***Early diagnosis can change the disease course due to effective treatment.*** - Screening is primarily recommended when **early detection** allows for interventions that effectively alter the natural history of the disease, improving prognosis or preventing progression. - For colorectal cancer, early diagnosis through screening allows for timely removal of **precancerous polyps** or early-stage cancers, significantly increasing survival rates. *The condition has a low case fatality rate.* - Conditions with low case fatality rates generally do not warrant extensive screening programs, as the **benefit-to-harm ratio** is often unfavorable. - Colorectal cancer, if undiagnosed and untreated, has a significant **case fatality rate**, making screening beneficial. *Diagnostic tools are not available.* - Screening is only conducted when **reliable, accurate, and cost-effective diagnostic tools** are available to detect the disease or its precursors in asymptomatic individuals. - If diagnostic tools are unavailable, screening would be impossible or ineffective, as there would be no way to identify those with the condition. *There is no effective treatment available.* - Screening is not typically recommended for diseases for which there is **no effective treatment**, as early detection would not improve patient outcomes. - The primary purpose of screening is to identify individuals who can benefit from **early intervention** and treatment to prevent serious morbidity or mortality.
Dental
1 questionsDuring which sleep stage does bruxism typically occur?
NEET-PG 2013 - Dental NEET-PG Practice Questions and MCQs
Question 21: During which sleep stage does bruxism typically occur?
- A. REM
- B. NREM stage 3, 4 (Correct Answer)
- C. NREM stage 1 and 2
- D. None of the options
Explanation: ***NREM stage 3, 4*** - **Bruxism**, or teeth grinding, most commonly occurs during **deep sleep stages**, specifically NREM stages 3 and 4 (often grouped as **slow-wave sleep**). - These stages are characterized by **delta waves** on EEG and are the deepest phases of sleep. *NREM stage 1 and 2* - **NREM stage 1** is a transitional stage from wakefulness to sleep, and **NREM stage 2** is a light sleep stage. - While some sleep-related events can occur, **bruxism** is less frequent and severe during these lighter sleep stages compared to deep sleep. *REM* - **REM sleep** is characterized by vivid dreaming, muscle atonia (paralysis), and rapid eye movements. - Due to **muscle atonia**, significant teeth grinding and jaw clenching are generally inhibited during this stage. *None of the options* - This option is incorrect because bruxism is a well-documented **sleep disorder** with a known association with specific sleep stages. - Research consistently points to **NREM deep sleep** as the primary period for bruxism activity.
Internal Medicine
2 questionsWhich of the following statements regarding falciparum malaria is false?
Which condition is primarily associated with tetany?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 21: Which of the following statements regarding falciparum malaria is false?
- A. Haemoglobinuria and renal failure
- B. Hypoglycemia
- C. Cerebral malaria
- D. Adequately prevented with chloroquine therapy (Correct Answer)
Explanation: ***Adequately prevented with chloroquine therapy*** - This statement is **false** because many strains of *Plasmodium falciparum* are now **resistant to chloroquine**, making it ineffective for prevention or treatment in most endemic areas [1]. - The widespread **drug resistance** of *P. falciparum* to chloroquine means it is no longer considered an adequate preventative measure. *Haemoglobinuria and renal failure* - These are **true** complications of severe *Falciparum malaria*, often termed **"blackwater fever"**, due to massive **intravascular hemolysis** and subsequent **acute kidney injury** [1]. - Renal failure can result from **hemoglobinuria**, **hypovolemia**, and **acidosis** associated with severe infection. *Hypoglycemia* - **Hypoglycemia** is a **true** and life-threatening complication of severe *Falciparum malaria*, particularly in children, pregnant women, and patients treated with **quinine** [1]. - It occurs due to increased **glucose consumption** by parasites and host cells, impaired **gluconeogenesis**, and drug-induced **insulin secretion**. *Cerebral malaria* - **Cerebral malaria** is a **true**, severe, and often fatal neurological complication of *Falciparum malaria*, characterized by **impaired consciousness** or **coma** [1]. - It is caused by **sequestration** of parasitized red blood cells in the **cerebral microvasculature**, leading to **microcirculatory obstruction** and inflammation.
Question 22: Which condition is primarily associated with tetany?
- A. None of the options
- B. Hyperparathyroidism
- C. Hypercalcemia
- D. Hypocalcemia (Correct Answer)
Explanation: ***Hypocalcemia*** - **Tetany** is a neuromuscular hyperexcitability state resulting from critically low levels of **ionized calcium** in the extracellular fluid [2]. - Reduced extracellular calcium increases neuronal membrane excitability, leading to spontaneous and repetitive nerve discharges and muscle contractions. *Hypercalcemia* - **Hypercalcemia** refers to elevated calcium levels, which *decreases* neuromuscular excitability. - Symptoms typically involve **fatigue, weakness, constipation, and kidney stones**, rather than tetany [1]. *Hyperparathyroidism* - **Primary hyperparathyroidism** is a common cause of **hypercalcemia** due to increased PTH secretion [3]. - Therefore, it leads to symptoms associated with high calcium, not low calcium and tetany. *None of the options* - This option is incorrect because **hypocalcemia** is a well-established cause of tetany.
Obstetrics and Gynecology
1 questionsWhich type of pelvis is most suitable for childbirth in females?
NEET-PG 2013 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 21: Which type of pelvis is most suitable for childbirth in females?
- A. Gynaecoid (Correct Answer)
- B. Android
- C. Anthropoid
- D. Platypelloid
Explanation: ***Gynaecoid*** - The **gynaecoid pelvis** is considered the classic female pelvis, with an **adequate, rounded inlet** and spacious dimensions that are optimal for vaginal delivery. - It has a wide and deep sacral curve, a wide subpubic angle, and parallel side walls, all facilitating the passage of the fetal head. *Android* - The **android pelvis** is typically male-like, characterized by a **heart-shaped or wedge-shaped inlet** and a narrow subpubic angle. - This shape makes it more difficult for the fetal head to engage and descend, often leading to prolonged labor or necessitating a cesarean section. *Anthropoid* - The **anthropoid pelvis** has an **oval-shaped inlet** that is wider in the anterior-posterior diameter and narrower in the transverse diameter. - While possible for delivery, the narrow transverse diameter can sometimes lead to difficulty with engagement or require a persistent occiput posterior presentation. *Platypelloid* - The **platypelloid pelvis** is characterized by a **flat, transverse oval inlet** and a short anterior-posterior diameter. - This shape is the least common and presents significant challenges for vaginal delivery, as the fetal head may not be able to engage due to the narrow anterior-posterior diameter.
Ophthalmology
1 questionsCataract is caused by all except:
NEET-PG 2013 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 21: Cataract is caused by all except:
- A. Ultraviolet radiation
- B. Infrared radiation
- C. Microwave radiation
- D. MRI (Correct Answer)
Explanation: ***MRI*** - Magnetic Resonance Imaging (MRI) uses powerful **magnetic fields** and radio waves to generate images, which are not known to cause cataracts. - The energy used in MRI is **non-ionizing** and does not directly damage lens proteins. *Ultraviolet radiation* - Prolonged exposure to **UV-B radiation** is a significant risk factor for the development of various types of cataracts, especially cortical and posterior subcapsular cataracts. - UV radiation can cause oxidative damage to lens proteins and lipids, leading to their aggregation and opacification. *Infrared radiation* - Chronic exposure to high levels of **infrared (IR) radiation**, such as that experienced by glassblowers or steelworkers, can lead to "glassblower's cataract" or "heat cataract." - IR radiation causes thermal damage to the lens, particularly the anterior capsule and subcapsular region. *Microwave radiation* - High-intensity **microwave radiation** has been implicated in the formation of cataracts, particularly in occupational exposure scenarios. - It causes thermal effects within the lens due to absorption of energy, leading to protein denaturation and opacification.
Pathology
1 questionsWhich of the following is not seen in Aschoff bodies?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 21: Which of the following is not seen in Aschoff bodies?
- A. Aschoff cells
- B. Fibroblasts
- C. Giant cells
- D. Polymorphonuclear cells (Correct Answer)
Explanation: ***Polymorphonuclear cells*** - **Aschoff bodies** are associated with rheumatic fever and typically contain **lymphocytes and macrophages**, not polymorphonuclear cells [1]. - The presence of **PMNs** would suggest an acute inflammatory response, which is not characteristic of Aschoff bodies. *Giant cells* - **Giant cells**, formed by the fusion of macrophages, can be found within Aschoff bodies. - They are indicative of **chronic inflammation**, presenting in conditions like rheumatic heart disease. *Aschoff cells* - **Aschoff cells** are a specific type of macrophage found within Aschoff bodies and are hallmark features of rheumatic fever [1]. - These cells are derived from activated macrophages and participate in **granulomatous inflammation**. *Fibroblasts* - **Fibroblasts** can also be present in Aschoff bodies, contributing to the **fibrous tissue** formation during the healing process. - They are involved in tissue repair and are found in various inflammatory conditions, including rheumatic fever. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 566.
Psychiatry
1 questionsWhat is the total score in the Mini Mental Status Examination (MMSE)?
NEET-PG 2013 - Psychiatry NEET-PG Practice Questions and MCQs
Question 21: What is the total score in the Mini Mental Status Examination (MMSE)?
- A. 25
- B. 32
- C. 30 (Correct Answer)
- D. 35
Explanation: ***Correct: 30*** - The **Mini Mental State Examination (MMSE)** is a 30-point questionnaire used to screen for **cognitive impairment** and monitor changes in cognitive function over time. - The score is calculated by summing points for correct responses across various cognitive domains such as **orientation**, **attention**, **memory**, **language**, and **visuospatial skills**. - This is the **maximum total score** achievable on the MMSE. *Incorrect: 25* - A score of 25 in the MMSE is significantly below the maximum, and depending on age and education, it often suggests **mild cognitive impairment** or early **dementia**. - While 25 is a possible score a patient can achieve, it is not the **maximum total score** for the examination itself. *Incorrect: 32* - The MMSE is standardized to have a maximum score of **30**, so 32 is higher than the possible range for this particular cognitive assessment tool. - No domain in the MMSE allows for a score that would lead to a total of 32 points. *Incorrect: 35* - Like 32, a score of 35 is beyond the **maximum achievable score** on the MMSE. - This indicates a misunderstanding of the MMSE's scoring rubric, as the highest possible score is **30 points**.
Surgery
1 questionsTest to differentiate between psychological and organic erectile dysfunction is:
NEET-PG 2013 - Surgery NEET-PG Practice Questions and MCQs
Question 21: Test to differentiate between psychological and organic erectile dysfunction is:
- A. Pharmacologically induced penile erection therapy
- B. Sildenafil induced erection
- C. Squeeze technique
- D. Nocturnal penile tumescence (Correct Answer)
Explanation: ***Nocturnal penile tumescence*** - **Nocturnal penile tumescence (NPT)** testing measures the occurrence and quality of **erections during sleep**. - Healthy men experience erections during REM sleep; their presence suggests a **psychological cause** for erectile dysfunction as the neural pathways for erection are intact. *Pharmacologically induced penile erection therapy* - This involves injecting **vasodilating agents** directly into the penis to induce an erection. - While it can confirm the capacity for erection, it does not differentiate between psychological and organic causes since both types of ED can respond to direct pharmacological intervention. *Sildenafil induced erection* - Sildenafil (Viagra) is a **PDE5 inhibitor** that works by enhancing the effects of nitric oxide during sexual stimulation. - An erection induced by sildenafil can occur in both psychological and organic ED as long as there is some capacity for vasodilation, thus it does not differentiate the underlying cause. *Squeeze technique* - The **squeeze technique** is a behavioral therapy used to treat **premature ejaculation**, not erectile dysfunction. - It involves stopping stimulation at the point of impending ejaculation and applying pressure to the penis to reduce arousal.