NEET-PG 2019 Practice Questions

Q: Mark the false statement regarding mitochondrial DNA:

Does not show heteroplasmy. ***Does not show heteroplasmy*** - This statement is false because **mitochondrial DNA (mtDNA)** commonly exhibits **heteroplasmy**, meaning the presence of more than one type of mitochondrial genome within a cell or individual. - **Heteroplasmy** arises due to the presence of both normal and mutated mtDNA, which can be passed down from the mother. *AGA and AGG are stop codons in mitochondrial DNA* - This statement is true; in the **universal genetic code**, AGA and AGG code for **arginine**, but in **human mitochondrial DNA**, they serve as **stop codons**. - This is an example of the **differences** in genetic code interpretation between the nuclear genome and the mitochondrial genome. *Kearns-Sayre Syndrome is a large deletion in mitochondrial DNA* - This statement is true; **Kearns-Sayre Syndrome** is a well-known mitochondrial disorder caused by a **large single deletion** in the mitochondrial DNA. - This deletion often leads to chronic progressive **external ophthalmoplegia**, **retinal pigmentary degeneration**, and **cardiac conduction defects**. *1% of cellular DNA, 13 proteins of respiratory chain* - This statement is true; **mitochondrial DNA constitutes** approximately **1% of the total cellular DNA** by mass. - It codes for **13 essential proteins** that are part of the **electron transport chain** (respiratory chain) complexes in the mitochondrion, along with ribosomal RNAs (rRNAs) and transfer RNAs (tRNAs).

Q: In type I diabetes, which of the following is the MOST characteristic metabolic change that distinguishes it from type II diabetes:-

Increased lipolysis. ***Increased lipolysis*** - In **type 1 diabetes** (T1D), there is an **absolute deficiency of insulin**, which is a potent **anti-lipolytic hormone**. [1] - This lack of insulin leads to unopposed **lipolysis**, resulting in increased free fatty acid (FFA) release, which can be metabolized into **ketone bodies** and contribute to **diabetic ketoacidosis (DKA)**. [2] *Increased protein catabolism* - While protein catabolism is increased in uncontrolled T1D due to the lack of insulin and increased counter-regulatory hormones, it is not the *most characteristic* metabolic change that clearly distinguishes it from type 2 diabetes (T2D), especially in early stages of T2D where some insulin may still be present. [1] - **Protein breakdown** produces amino acids for gluconeogenesis, contributing to hyperglycemia, but **lipolysis leading to ketosis** is more specific to severe insulin deficiency. [3] *Decreased glucose uptake* - **Decreased glucose uptake** by peripheral tissues (especially muscle and adipose tissue) is a characteristic feature of both T1D and T2D. [1] - In T1D, it's due to insulin deficiency, while in T2D, it's primarily caused by **insulin resistance**, making it less specific to distinguish T1D. *Increased hepatic glucose output* - **Increased hepatic glucose output** is a significant contributor to hyperglycemia in both T1D and T2D. [1] - In T1D, it's due to the lack of insulin's suppressive effect on the liver, whereas in T2D, it's due to **hepatic insulin resistance** and increased gluconeogenesis.

Q: Which amino acid is involved in the synthesis of creatinine, NO, and urea?

Arginine. ***Arginine*** - **Arginine** is a precursor for **Nitric Oxide (NO)** synthesis via **nitric oxide synthase**. - It is also a substrate for **creatinine** synthesis (along with glycine and methionine) and plays a key role in the **urea cycle**. *Glycine* - **Glycine** is a precursor for **creatinine** synthesis, but not directly involved in NO or urea production as the primary amino acid. - It is also a component of glutathione and purine synthesis. *Aspartate* - **Aspartate** is a key intermediate in the **urea cycle**, contributing one nitrogen atom to urea. - It is not directly a precursor for NO or creatinine. *Citrulline* - **Citrulline** is an intermediate in the **urea cycle** and is converted to arginine. - It is not directly involved in the synthesis of creatinine or as the primary precursor for NO.

Q: A man who is chronic alcoholic will develop which type of cardiomyopathy?

Dilated cardiomyopathy. ***Dilated cardiomyopathy*** - Chronic alcohol abuse is a major cause of **dilated cardiomyopathy**, where the heart's pumping chambers (ventricles) become enlarged and weakened, leading to reduced cardiac output [1]. - This condition often called **alcoholic cardiomyopathy**, is characterized by **ventricular dilation** and **systolic dysfunction**. *Hypertrophic cardiomyopathy* - This condition involves thickening of the heart muscle, often genetic, and is not directly caused by **chronic alcoholism**. - While alcohol can worsen pre-existing heart conditions, it does not typically lead to primary **hypertrophic cardiomyopathy**. *Myocarditis* - **Myocarditis** is an inflammation of the heart muscle, usually caused by viral infections or autoimmune processes. - Although heavy alcohol use can weaken the immune system, it is not a direct cause of viral or primary inflammatory myocarditis. *Pericarditis* - **Pericarditis** is the inflammation of the pericardium, the sac surrounding the heart, most commonly due to viral infections or autoimmune conditions. - While alcohol abuse can have various systemic effects, it is not a recognized direct cause of **pericarditis**.

Q: Which of the following is autosomal dominant in inheritance?

Achondroplasia. ***Achondroplasia*** - This condition is inherited in an **autosomal dominant** pattern, meaning only one copy of the mutated gene is needed to cause the disorder. - It is caused by a mutation in the **FGFR3 gene**, leading to abnormal bone growth and short-limbed dwarfism [1]. *Hemochromatosis* - This condition is primarily inherited in an **autosomal recessive** pattern, meaning two copies of the mutated gene (HFE gene) are required for the disease to manifest. - It leads to excessive iron absorption and organ damage. *Sickle cell disease* - This is an **autosomal recessive** disordertoo. - It results from a mutation in the **HBB gene**, affecting hemoglobin and causing red blood cells to become sickle-shaped. *Wiskott Aldrich syndrome* - This is an **X-linked recessive** disorder, meaning it primarily affects males. - It involves mutations in the **WAS gene**, leading to immunodeficiency, eczema, and thrombocytopenia.

Q: A 9 years old child presented to OPD with complaints of high grade fever, vomiting, one episode of seizure. CSF examination was done and Gram staining of the culture showed the following finding. What is the probable causative agent?

Gram-positive diplococci (e.g., Streptococcus pneumoniae). ***Gram-positive diplococci (e.g., Streptococcus pneumoniae)*** - The image displays small, purple (Gram-positive) cocci arranged in pairs (**diplococci**). - *Streptococcus pneumoniae* is a common cause of **bacterial meningitis** in children, and its characteristic morphology on Gram stain is Gram-positive diplococci. *Gram-negative coccobacilli (e.g., Haemophilus influenzae)* - While *Haemophilus influenzae* can cause meningitis in children, its Gram stain morphology would show **pink-stained coccobacillary forms**, not purple cocci. - The bacteria in the image are clearly cocci, not coccobacilli, and stain Gram-positive (purple). *Gram-negative diplococci (e.g., Neisseria meningitidis)* - *Neisseria meningitidis* is a significant cause of meningitis and appears as **Gram-negative (pink) diplococci**. - The organisms in the image are stained purple, indicating they are Gram-positive. *Gram-positive cocci in chains (e.g., Streptococcus pyogenes)* - *Streptococcus pyogenes* typically forms **chains of Gram-positive cocci**, which is not the predominant arrangement seen in the image. - Although it is Gram-positive, the characteristic arrangement in the image is diplococci, not chains.

Q: Flask shaped ulcers in colon are caused by:-

Entamoeba histolytica. ***Entamoeba histolytica*** - *Entamoeba histolytica* is a protozoan parasite that invades the **colonic mucosa**, leading to characteristic **flask-shaped ulcers**. - These ulcers are formed as the trophozoites penetrate the epithelium and spread laterally through the submucosa, creating a narrow neck at the mucosal surface and a wider base below. *Giardia lamblia* - *Giardia lamblia* causes **giardiasis**, primarily affecting the **small intestine** and leading to malabsorption and diarrhea. - It typically does not cause invasive disease or ulcer formation in the colon, instead, it attaches to the intestinal villi. *Enterobius vermicularis* - *Enterobius vermicularis* is an intestinal nematode (pinworm) that causes **enterobiasis**, commonly manifesting as **perianal itching**, especially at night. - It is a non-invasive parasite and does not cause ulcers in the colon. *H. Pylori* - *H. pylori* is a bacterium primarily associated with infections of the **stomach** and **duodenum**, causing gastritis, peptic ulcers, and increasing the risk of gastric cancer. - It does not colonize the colon or cause flask-shaped ulcers.

Q: Bilateral grasp is seen at what age?

5 months. ***5 months*** - At **5 months**, infants typically develop the ability to **reach for and grasp objects with both hands**, demonstrating improved coordination and control. - This age marks a transition from reflexive grasping to more intentional and bilateral manipulation of objects. *6 months* - While fine motor skills continue to develop at 6 months, **bilateral grasp** is usually well-established by this age, having emerged earlier. - At 6 months, infants are often progressing towards **unilateral grasp** and transferring objects between hands. *3 months* - At **3 months**, infants are typically still developing head control and beginning to reach, but their grasp is often still a **reflexive palmar grasp** rather than intentional bilateral grasping. - Reaching at this age is usually more swiping or batting at objects rather than a coordinated grasp. *9 months* - By **9 months**, infants have developed more refined pincer grasp and are capable of complex manipulation of objects with a single hand. - **Bilateral grasp** is a much earlier developmental milestone than the advanced skills seen at 9 months.

Q: DOC for prophylaxis against Diphtheria is:-

Erythromycin. ***Erythromycin*** - **Erythromycin** is the drug of choice for prophylaxis and treatment of diphtheria, especially in individuals exposed to a confirmed case. - It works by inhibiting protein synthesis in *Corynebacterium diphtheriae*, preventing bacterial multiplication and toxin production. *Cloxacillin* - **Cloxacillin** is a narrow-spectrum penicillinase-resistant penicillin primarily used for treating staphylococcal infections. - It is not effective against *Corynebacterium diphtheriae* and therefore not used for diphtheria prophylaxis. *Rifampicin* - **Rifampicin** is an antibiotic commonly used for tuberculosis and prophylaxis against meningococcal disease. - It does not have significant activity against *Corynebacterium diphtheriae* and is not indicated for diphtheria prevention. *Ciprofloxacin* - **Ciprofloxacin** is a fluoroquinolone antibiotic with a broad spectrum of activity against many bacterial infections. - While it can be used for some respiratory infections, it is not the recommended antibiotic for diphtheria prophylaxis.

Question 1

Mark the false statement regarding mitochondrial DNA:

Accepted Answer

Does not show heteroplasmy

Answer

AGA and AGG are stop codons in mitochondrial DNA

Answer

Kearns-Sayre Syndrome is a large deletion in mitochondrial DNA

Answer

1% of cellular DNA, 13 proteins of respiratory chain

Question 2

In type I diabetes, which of the following is the MOST characteristic metabolic change that distinguishes it from type II diabetes:-

Accepted Answer

Increased lipolysis

Answer

Increased protein catabolism

Answer

Decreased glucose uptake

Answer

Increased hepatic glucose output

Question 3

Which amino acid is involved in the synthesis of creatinine, NO, and urea?

Accepted Answer

Arginine

Answer

Glycine

Answer

Aspartate

Answer

Citrulline

Question 4

A man who is chronic alcoholic will develop which type of cardiomyopathy?

Accepted Answer

Dilated cardiomyopathy

Answer

Hypertrophic cardiomyopathy

Answer

Myocarditis

Answer

Pericarditis

Question 5

Which of the following is autosomal dominant in inheritance?

Accepted Answer

Achondroplasia

Answer

Hemochromatosis

Answer

Sickle cell disease

Answer

Wiskott Aldrich syndrome

Question 6

A 9 years old child presented to OPD with complaints of high grade fever, vomiting, one episode of seizure. CSF examination was done and Gram staining of the culture showed the following finding. What is the probable causative agent?

Accepted Answer

Gram-positive diplococci (e.g., Streptococcus pneumoniae)

Answer

Gram-negative coccobacilli (e.g., Haemophilus influenzae)

Answer

Gram-negative diplococci (e.g., Neisseria meningitidis)

Answer

Gram-positive cocci in chains (e.g., Streptococcus pyogenes)

Question 7

Flask shaped ulcers in colon are caused by:-

Accepted Answer

Entamoeba histolytica

Answer

Giardia lamblia

Answer

Enterobius vermicularis

Answer

H. Pylori

Question 8

Which of the following is most specific for congenital Rubella syndrome?

Accepted Answer

Triad of CRS are cataract, cardiac defects, sensorineural deafness

Answer

Blueberry muffin rash is seen

Answer

Infection is most serious in the first trimester of pregnancy

Answer

Virus can be isolated up to 12 months after birth

Question 9

Bilateral grasp is seen at what age?

Accepted Answer

5 months

Answer

6 months

Answer

3 months

Answer

9 months

Question 10

DOC for prophylaxis against Diphtheria is:-

Accepted Answer

Erythromycin

Answer

Cloxacillin

Answer

Rifampicin

Answer

Ciprofloxacin

NEET-PG 2019

Biochemistry

Internal Medicine

Microbiology

Pediatrics

Pharmacology