Biochemistry MCQs with Answer and Explanations | Chapter 7

Answer: Hgb C

At alkaline pH, hemoglobin molecules carry a negative charge. The speed at which they migrate towards the positive electrode (anode) during electrophoresis depends on their net charge. Hgb C has a slower migration rate compared to the other options due to its altered amino acid sequence, which affects its overall charge.

The other options are incorrect:

• Hgb F: The predominant hemoglobin in fetuses, it migrates faster than Hgb C at alkaline pH.
• Hgb A: This is the most common adult hemoglobin and migrates faster than Hgb C at alkaline pH.
• Hgb S: Migrates between Hgb A2 and Hgb F, but still faster than Hgb C.

Answer: Intestine

Urobilinogen is formed in the intestine as a result of the breakdown of bilirubin by intestinal bacteria. Bilirubin, which is a byproduct of hemoglobin degradation, is converted to urobilinogen in the intestines.

The other options are incorrect:

• Liver: The liver processes bilirubin, a precursor to urobilinogen, but the actual conversion takes place in the intestines.
• Kidney: The kidney is involved in the excretion of urobilinogen, but it is not where it is formed.
• Spleen: The spleen is primarily involved in the breakdown of old red blood cells and the recycling of iron, but it does not produce urobilinogen.

Answer: Brain tissue

Kernicterus is an abnormal accumulation of bilirubin in the brain tissue. High levels of unconjugated bilirubin can cross the blood-brain barrier in newborns, leading to this condition, which can cause severe neurological damage.

The other options are incorrect:

• Kidney tissue: Bilirubin is excreted by the kidneys, but its accumulation in the kidneys does not cause kernicterus.
• Heart tissue: Bilirubin accumulation primarily affects the brain, not the heart.
• Liver tissue: The liver is involved in bilirubin metabolism, but kernicterus is about the deposition of bilirubin in other tissues, not the liver itself.

Answer: Occult blood

A black, tarry stool, often referred to as melena, is a strong indicator of upper gastrointestinal bleeding. The blood is digested as it travels through the digestive tract, turning it black and tarry. Occult blood refers to blood that is hidden in the stool and not visible to the naked eye.

The other options are incorrect:

• Excess mucus: While mucus can be present in stool, it does not cause the black, tarry appearance.
• Fecal fat: This is associated with malabsorption issues and typically presents with a different appearance than black, tarry stools.
• Trypsin: This is an enzyme involved in protein digestion and is not related to stool color.

Answer: Lipase

Lipase is the most specific enzyme test for diagnosing acute pancreatitis. It is produced by the pancreas and is released into the bloodstream when the pancreas is inflamed.

The other options are incorrect:

• Amylase: Another enzyme produced by the pancreas, but less specific than lipase for diagnosing pancreatitis. It can be elevated in other conditions as well.
• Acid phosphatase: Primarily associated with the prostate gland.
• Trypsin: While involved in digestion, it is less specific for pancreatitis than lipase.

Answer: Amylase (AMS) and lipase (LPS)

Amylase and lipase are enzymes produced by the pancreas. When the pancreas is inflamed (acute pancreatitis), these enzymes are released into the bloodstream, causing their levels to rise. Therefore, measuring the levels of amylase and lipase is crucial in diagnosing acute pancreatitis.

The other options are incorrect:

• Aspartate aminotransferase (AST) and lactate dehydrogenase (LD): While these enzymes can be elevated in various conditions, they are not specific markers for pancreatitis.
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT): These enzymes are primarily associated with liver function, not pancreatic function.
• 5′ -nucleotidase (5’N) and gamma-glutamyl transferase (GGT): These enzymes are also related to liver function and biliary system disorders.

Answer: Amylase (AMS)

Amylase is an enzyme primarily responsible for breaking down complex carbohydrates like starch into simpler sugars, including glucose and maltose.

The other options are incorrect:

• Isocitric dehydrogenase (ICD): Also part of the citric acid cycle, it catalyzes a different step in the process.
• Malate dehydrogenase (MD): Involved in the citric acid cycle, it catalyzes a different reaction.
• Creatine kinase (CK): Primarily associated with muscle metabolism and energy production.

Answer: Liver

AST, or aspartate aminotransferase, is an enzyme primarily found in the liver, heart, skeletal muscle, and kidney. However, it is most commonly used as a marker for liver damage. Elevated AST levels typically indicate liver cell injury or inflammation.

The other options are incorrect:

• Pancreas: Pancreatitis typically involves elevations in enzymes like amylase and lipase, not AST.
• Kidney: While AST is present in kidney tissue, it is not primarily used as a marker for kidney disease.
• Intestine: AST is not a significant enzyme in the intestine.

Answer: Viral hepatitis

Both AST (aspartate aminotransferase) and ALT (alanine aminotransferase) are primarily liver enzymes. When the liver is damaged, as in viral hepatitis, these enzymes are released into the bloodstream, causing elevated levels.

The other options are incorrect:

• Infectious mononucleosis: While it can cause liver involvement, the elevation of AST and ALT is usually less pronounced compared to viral hepatitis.
• Muscular dystrophy: Primarily affects muscle tissue, leading to elevated creatine kinase (CK) levels, not AST and ALT.
• Pulmonary emboli: Primarily affects the lungs and respiratory system, not the liver.

Answer: Acute viral hepatitis

Acute viral hepatitis causes significant damage to liver cells, leading to a massive release of AST and ALT into the bloodstream. This results in the highest levels of these enzymes compared to other liver conditions.

The other options are incorrect:

• Alcoholic cirrhosis: Chronic alcohol abuse leads to liver damage, but the elevation of AST and ALT is often less pronounced than in acute viral hepatitis.
• Primary biliary cirrhosis: A chronic liver disease characterized by damage to bile ducts, causing elevated alkaline phosphatase and gamma-glutamyl transferase (GGT) primarily. AST and ALT levels are usually moderately elevated.
• Metastatic hepatic cirrhosis: This is a late-stage condition where cancer has spread to the liver. While it can cause liver damage, the degree of enzyme elevation is typically less dramatic than in acute viral hepatitis.

Answer: Pernicious anemia

Lactate dehydrogenase (LDH) isoenzyme 1 is most significantly elevated in pernicious anemia. This condition involves vitamin B12 deficiency, which affects the production and maturation of red blood cells, leading to increased LDH levels, particularly the LDH-1 isoenzyme, which is predominant in red blood cells.

The other options are incorrect:

• Pancreatitis: Pancreatitis is associated with elevations in LDH, but it often involves LDH isoenzyme 4 and 5, reflecting liver and muscle damage rather than isoenzyme 1.
• Pneumonia: Pneumonia can cause elevations in LDH, but it typically involves LDH isoenzyme 2 rather than isoenzyme 1. The elevation is related to lung tissue damage and inflammation.
• Glomerulonephritis: Glomerulonephritis can cause LDH elevations, but these are usually less specific and do not primarily involve LDH isoenzyme 1.

Answer: Lactate dehydrogenase

Lactate dehydrogenase (LDH) is an enzyme widely distributed in various tissues of the body. It can be separated into five different molecular forms or isoenzymes (LDH-1 to LDH-5) through electrophoresis, each with a slightly different composition.

The other options are incorrect:

• Creatine kinase: Primarily associated with muscle tissue and energy metabolism.
• Lipase: Primarily involved in fat digestion.
• Transaminase: A general term for enzymes involved in amino acid metabolism, not known for multiple isoenzymes.

Answer: Specimen hemolysis

Specimen hemolysis is a common cause of falsely increased LD1 fraction of lactate dehydrogenase (LDH). Hemolysis releases LDH from red blood cells into the serum, leading to artificially high levels of LD1, which is predominantly found in red blood cells.

The other options are incorrect:

• Drug toxicity: While some drugs can affect liver enzymes, they typically don’t cause isolated increases in LD1.
• Liver disease: Primarily associated with elevations in LD-4 and LD-5.
• Congestive heart failure: Can lead to elevations in LDH, but not specifically LD1.

Answer: CKMB

CKMB is a specific isoenzyme of creatine kinase primarily found in cardiac muscle. When there is damage to the heart muscle, such as in a myocardial infarction (heart attack), CKMB levels rise significantly.

The other options are incorrect:

None: CKMB is specifically indicative of acute myocardial damage.

CKMM: The most common form of creatine kinase, primarily found in skeletal muscle.

CKBB: Found primarily in brain tissue.

Answer: Hepatitis

Creatine kinase (CK) is primarily associated with muscle tissue. Conditions affecting the heart or skeletal muscles typically lead to elevated CK levels. Hepatitis primarily affects the liver and would not cause a significant increase in CK.

The other options are incorrect:

• Intramuscular injection: Can cause temporary muscle damage and a slight increase in CK levels.
• Acute myocardial infarct: Damage to heart muscle releases CK into the bloodstream, leading to elevated levels.
• Progressive muscular dystrophy: A muscle-wasting disease that causes significant muscle damage and elevated CK levels.

Answer: Liver disease

Lactate dehydrogenase (LDH) isoenzymes 4 and 5 are most often elevated in liver disease. These isoenzymes are predominantly found in the liver, and their levels rise when liver cells are damaged, as seen in conditions like hepatitis or cirrhosis.

The other options are incorrect:

• Pulmonary edema: While LDH levels might be elevated due to tissue damage, it’s not specifically associated with LDH isoenzymes 4 and 5.
• Hemolytic anemia: Primarily associated with an elevation in LDH-1.
• Myocardial infarction: Primarily associated with an elevation in LDH-1.

Answer: CK

When a myocardial infarction (heart attack) occurs, creatine kinase (CK), particularly the CK-MB isoenzyme, is the first enzyme to become elevated. CK-MB levels rise within 3-6 hours after the onset of myocardial injury, making it an early marker for heart damage.

The other options are incorrect:

• LD (Lactate Dehydrogenase): Elevates later than CK, typically peaking 2-3 days after the onset of symptoms.
• AST (Aspartate Aminotransferase): Primarily associated with liver damage, although it can also be elevated in myocardial infarction but at a later stage.
• ALT (Alanine Aminotransferase): Primarily a liver enzyme and is not a significant marker for myocardial infarction.

Answer: M subunit is inactivated

In the immunoinhibition phase of the CK-MB procedure, an antibody specific to the M subunit of creatine kinase is added. This antibody binds to and inactivates the M subunit, leaving only the B subunit active. The activity of the remaining B subunit is then measured to calculate the CK-MB level.

The other options are incorrect:

• BB is inactivated: BB is not involved in the CK-MB assay.
• B subunit is inactivated: This is incorrect as the B subunit is the one being measured.
• MB is inactivated: The goal of the procedure is to measure MB, not inactivate it.

Answer: Myocardial infarction

Increased CKMB activity on a CK electrophoresis pattern is most likely found in a patient suffering from a myocardial infarction (heart attack). CKMB is an isoenzyme specific to heart muscle, and its elevation is a key indicator of myocardial damage.

The other options are incorrect:

• Severe head injury: Severe head injury could elevate CK-BB, the isoenzyme found in the brain, but it does not significantly elevate CKMB, which is specific to the heart.
• Acute muscular stress following strenuous exercise: Strenuous exercise primarily elevates CK-MM, the isoenzyme found in skeletal muscles, not CK-MB.
• Malignant liver disease: Liver disease does not typically elevate CKMB; it might affect liver enzymes such as ALT and AST instead.

Answer: Hemolytica anemia

LDH-1 and LDH-2 are predominantly found in red blood cells. In hemolytic anemia, there is increased destruction of red blood cells, leading to the release of LDH-1 and LDH-2 into the bloodstream, resulting in elevated levels of these fast fractions.

The other options are incorrect:

• Hepatic damage: While it can lead to increased LDH levels, the elevation is typically in the slower fractions (LDH-4 and LDH-5).
• Nephrotic syndrome: Primarily affects the kidneys and would not cause a significant increase in LDH-1 and LDH-2.
• Pancreatitis: Primarily associated with elevations in amylase and lipase.

Answer: Placenta

Regan isoenzyme is an abnormal form of alkaline phosphatase that shares similar properties to the alkaline phosphatase originating from the placenta. It is often associated with certain malignancies and is used as a tumor marker.

The other options are incorrect:

• Intestine: Intestinal alkaline phosphatase originates from the intestine.
• Skeleton: Bone-specific alkaline phosphatase originates from the skeleton.
• Kidney: Renal alkaline phosphatase originates from the kidney.

Answer: Bone

The most heat-labile fraction of alkaline phosphatase is obtained from bone. Bone alkaline phosphatase is sensitive to heat and can be easily inactivated at lower temperatures compared to other isoenzymes.

The other options are incorrect:

• Placenta: Placental alkaline phosphatase is quite heat-stable and is often used as a reference for heat stability studies. It is not the most heat-labile fraction.
• Liver: Liver alkaline phosphatase is more heat-stable compared to the bone fraction and is not the most heat-labile form.
• Intestine: Intestinal alkaline phosphatase also has different heat stability characteristics but is not as heat-labile as the bone isoenzyme.

Answer: Gamma-glutamyl transferase (GGT)

GGT is the most sensitive enzymatic indicator of liver damage caused by ethanol intake. It is significantly elevated in individuals with chronic alcohol abuse, making it a valuable marker for monitoring alcohol-related liver disease.

The other options are incorrect:

• Alkaline phosphatase: While it can be elevated in liver disease, it is not as specific for alcohol-induced liver damage as GGT.
• Alanine aminotransferase (ALT): While ALT is elevated in liver damage, it is less specific for alcohol-induced liver injury compared to GGT.
• Aspartate aminotransferase (AST): Similar to ALT, AST is elevated in liver damage but is less specific for alcohol-related liver disease.

Answer: Specificity

Isoenzyme assays are performed to improve the specificity of a diagnostic test. By identifying specific isoenzymes, it’s possible to pinpoint the exact tissue or organ origin of the enzyme, leading to a more accurate diagnosis.

The other options are incorrect:

• Sensitivity: Refers to the ability of a test to correctly identify positive cases.
• Precision: Refers to the reproducibility of test results.
• Accuracy: Refers to how close a measurement is to the true value.

Answer: Apoenzyme

An apoenzyme is the protein component of an enzyme. It is the inactive form of the enzyme and requires a non-protein component called a cofactor to become active.

The other options are incorrect:

• Proenzyme: This is an inactive precursor of an enzyme that requires activation to become active.
• Coenzyme: This is a non-protein organic molecule that acts as a cofactor for an enzyme.
• Holoenzyme: This is the complete, active form of an enzyme, consisting of both the apoenzyme and its cofactor.

Answer: Acid phosphatase

Acid phosphatase is an enzyme found in high concentrations in seminal fluid. Its presence in a sample can be a strong indicator of the presence of semen.

The other options are incorrect:

• Alkaline phosphatase: Primarily associated with liver and bone function, it is not a marker for seminal fluid.
• Lactic dehydrogenase (LD): While present in seminal fluid, it is also found in other body tissues and is not as specific for semen as acid phosphatase.
• Isocitrate dehydrogenase (ICD): An enzyme involved in the citric acid cycle, it is not specifically elevated in seminal fluid.

Answer: Deficiency in lipoprotein lipase activity

Chylomicrons are large lipoproteins responsible for transporting dietary fats from the intestines to other tissues. Lipoprotein lipase is the enzyme that breaks down triglycerides in chylomicrons. A deficiency in this enzyme leads to an accumulation of chylomicrons in the blood, resulting in hypertriglyceridemia.

The other options are incorrect:

• Familial hypoalphalipoprotein: Characterized by low HDL cholesterol levels.
• Familial hypercholesterolemia: Primarily characterized by elevated LDL cholesterol levels.
• Hypertriglyceridemia: This is a general term for elevated triglyceride levels, but it doesn’t specify the underlying cause.

Answer: Chylomicrons

Turbidity in serum is primarily caused by the presence of chylomicrons, which are large particles carrying dietary fats. Their high concentration in the blood gives the serum a cloudy or milky appearance.

The other options are incorrect:

• Albumin: As a protein, albumin does not cause turbidity in serum.
• Cholesterol: While cholesterol is a lipid, it doesn’t typically cause the pronounced turbidity seen with chylomicrons.
• Total protein: Proteins don’t contribute significantly to serum turbidity.

Answer: Osmolality

Osmolality measures the concentration of solute particles in a solution. It is determined by measuring the freezing point depression of the solution. Therefore, freezing point depression measurements are an integral part of osmolality testing.

The other options are incorrect:

• Specific gravity: Measures the density of a solution compared to water, it is less precise than osmolality in determining the concentration of solutes.
• Refractive index: Measures the bending of light as it passes through a solution, primarily used to estimate specific gravity.
• Hydrometry: Uses a hydrometer to measure specific gravity, which is a less accurate method than osmolality for determining urine concentration.

Answer: Plasma only

Fibrinogen is a clotting factor present in plasma. Serum is plasma without the clotting factors, including fibrinogen. Therefore, fibrinogen determinations can only be performed on plasma.

The other options are incorrect:

• Any body fluid: Fibrinogen is a specific component of blood plasma and is not found in other body fluids.
• Serum only: Fibrinogen is absent in serum.
• Either serum or plasma: Fibrinogen is only present in plasma.

Answer: Uric acid

Uric acid is the final product of purine metabolism in humans. Purines are components of DNA and RNA, and their breakdown leads to the formation of uric acid, which is then excreted primarily through the kidneys.

The other options are incorrect:

• Urea: The end product of protein metabolism, not purine metabolism.
• Creatine: Creatinine is a breakdown product of creatine, which is related to muscle metabolism, not purine metabolism.
• Creatinine: A breakdown product of creatine, primarily used as a marker of kidney function.

Answer: Pseudomonas aeruginosa

Pseudomonas aeruginosa is a bacterium known for producing a variety of pigments, including water-soluble ones like pyocyanin and fluorescein. These pigments contribute to the characteristic blue-green color often associated with Pseudomonas infections.

Incorrect Options:

• Group A streptococcus: Primarily associated with hemolytic activity rather than pigment production.
• Yeasts: While some yeasts produce pigments, they are typically fat-soluble, not water-soluble.
• Staphylococcus epidermidis: Generally doesn’t produce significant pigments.

Answer: Obstructive jaundice

Alkaline phosphatase (ALP) is significantly elevated in obstructive jaundice. This condition occurs when bile flow from the liver to the gallbladder is blocked, leading to a backup of bile and increased ALP levels.

The other options are incorrect:

• Myocardial infarction: This condition primarily affects the heart and does not involve the liver or biliary system, so ALP levels would not be significantly elevated.
• Kidney disease: While ALP levels can be slightly elevated in kidney disease, they are not typically greatly elevated.
• Liver disease: ALP can be elevated in liver disease, but it’s usually not as dramatically increased as in obstructive jaundice.

Answer: Ketone bodies

Metabolic acidosis often results from an overproduction of ketone bodies, which are acidic substances. Testing urine for the presence of ketone bodies can help indicate the presence of metabolic acidosis. This is commonly seen in conditions like diabetic ketoacidosis.

The other options are incorrect:

• Glucose: Glucosuria is usually indicative of diabetes mellitus, not metabolic acidosis.
• Protein: Proteinuria is typically associated with kidney disease, not metabolic acidosis.
• Uric acid: Elevated uric acid levels are associated with gout and kidney disease, not metabolic acidosis.

Answer: 3-hydroxy butyric acid

Ketone bodies are produced in the liver during times of low carbohydrate intake or impaired glucose utilization. The three primary ketone bodies are acetoacetic acid, acetone, and 3-hydroxybutyric acid.

The other options are incorrect:

• Lactic acid: Produced during anaerobic glycolysis, unrelated to ketone body formation.
• Acetic acid: While similar in name, it’s not a ketone body.
• Oxaloacetic acid: Involved in the citric acid cycle, not ketone body metabolism.

Answer: Dip stick

The dip stick test for urinary glucose is specific and commonly used for detecting glucose in urine. It uses chemical reagents that specifically react with glucose, providing a straightforward and reliable result.

The other options are incorrect:

• Pandy: The Pandy test is used for detecting proteins, not glucose, in urine. It is not related to glucose testing.
• Benedict’s: The Benedict’s test is a qualitative test for reducing sugars, not specific to glucose alone. It detects a range of reducing sugars, including glucose, but is not specific for glucose.
• Clinitest: Clinitest is a qualitative test for reducing sugars, including glucose, but it is less specific than the dip stick test. It can detect other reducing sugars in addition to glucose.

Answer: Pale yellow

Dilute urine, which indicates good hydration, is typically pale yellow in color. The more concentrated the urine, the darker its color becomes.

The other options are incorrect:

• Amber: Similar to dark yellow, indicates concentrated urine.
• Dark yellow: Indicates dehydration or concentrated urine.
• Reddish-yellow: Suggests the presence of blood or certain medications.

Answer: Nitroprusside

The ketone test area on a dipstick is impregnated with nitroprusside. This chemical reacts with acetoacetic acid (one of the ketone bodies) to produce a color change, indicating the presence of ketones in the urine.

The other options are incorrect:

• 2,4 dichloraniline: Not used in ketone testing.
• Alkaline copper: Used for reducing sugars, not ketones.
• Ferric chloride: Primarily used in testing for salicylate overdose, not ketones.

Answer: Bound to globulin

Most of the plasma thyroxine (T4) is bound to thyroid-binding globulin (TBG), which is a type of globulin. This binding helps to regulate the availability of T4 and maintain its stability in the bloodstream.

The other options are incorrect:

• Bound to albumin: While a minor portion of T4 is bound to albumin, the majority of T4 is bound to thyroid-binding globulin (TBG). Albumin is not the primary binding protein for T4.
• Free: Only a small fraction of thyroxine (T4) is present in its free form. The majority is bound to proteins in the plasma.
• Bound to cholesterol: Thyroxine (T4) is not bound to cholesterol. It primarily binds to plasma proteins like thyroid-binding globulin, not cholesterol.

Answer: Light yellow or straw colored

Cerebrospinal fluid (CSF) in patients with post-cerebral hemorrhage often appears light yellow or straw-colored due to the presence of blood breakdown products, such as bilirubin, which color the fluid.

The other options are incorrect:

• Clear (colorless): Clear (colorless) CSF is the normal appearance of cerebrospinal fluid in the absence of pathology. It does not reflect the presence of blood or breakdown products from hemorrhage.
• Bright red: Bright red CSF indicates recent or active bleeding rather than post-cerebral hemorrhage. It would be seen in cases of acute hemorrhage.
• Green: Green CSF is not a typical color for cerebrospinal fluid and is not associated with post-cerebral hemorrhage. It may indicate infection or other specific conditions but not hemorrhage.

Answer: Osmolality

Osmolality measures the concentration of solute particles in a solution. It’s determined by measuring the freezing point depression, as the more particles present, the lower the freezing point.

The other options are incorrect:

• Specific gravity: Measures the density of a solution compared to water, less precise than osmolality for determining solute concentration.
• Hydrometry: Measures specific gravity, which is less accurate than osmolality in determining urine concentration.
• Refractive index: Measures the bending of light through a solution, primarily used to estimate specific gravity.

Answer: Osmotic pressure of body fluids

Sodium is a crucial electrolyte that plays a significant role in maintaining the body’s fluid balance. It helps regulate the osmotic pressure, which is the pressure exerted by a solution to prevent the inward flow of water across a semi-permeable membrane. This balance is essential for various bodily functions.

The other options are incorrect:

• Salt intake: Refers to the dietary consumption of sodium, not its physiological
• Blood coagulation: Primarily controlled by clotting factors.
• Cardiac muscle contractions: While sodium is involved in nerve and muscle function, it’s not the primary factor in cardiac contractions.

Answer: alpha and beta

Normal adult hemoglobin (Hb A) is composed of two alpha (α) and two beta (β) polypeptide chains. This structure is essential for the proper function of hemoglobin in carrying oxygen.

Incorrect Options:

• alpha and brotherton: There is no such polypeptide chain in hemoglobin.
• alpha and epsilon: These chains are typically found in fetal hemoglobin.
• alpha and delta: These chains form hemoglobin A2, a minor component of adult hemoglobin.

Answer: vitamin B

Vitamin B complex is a group of water-soluble vitamins that play crucial roles in various metabolic processes. Many of these vitamins function as coenzymes, which are essential for the activation of a wide range of enzymes.

The other options are incorrect:

• Vitamin D: Acts as a hormone, regulating calcium and phosphorus levels.
• Vitamin A: Primarily involved in vision, growth, and immune function.
• Vitamin C: An antioxidant with a role in collagen synthesis and immune function.

Answer: acid phosphatase

Acid phosphatase is an enzyme primarily produced by the prostate gland. Its presence and activity in semen are indicative of normal prostate function.

The other options are incorrect:

• Alkaline phosphatase: While present in the prostate, it’s not as specific for prostate function as acid phosphatase.
• Alanine transaminase (ALT): Primarily a liver enzyme.
• Aspartate transaminase (AST): Primarily a liver enzyme.

Answer: Hays test

Fouchet’s test is used to detect the presence of bile salts in urine. It involves the use of a reagent that reacts with bile salts to produce a characteristic color change.

The other options are incorrect:

• Hays test: The Hays test is not commonly used for detecting bile salts. It is not a standard test for this purpose.
• Benzidine test: The benzidine test is used to detect the presence of blood (hemoglobin) in urine, not bile salts.
• Ehrlich’s test: Ehrlich’s test is used to detect the presence of urobilinogen in urine, not bile salts.

Answer: Both 1 and 2

Ketone bodies are a group of substances produced by the liver when there is insufficient insulin in the body or when carbohydrates are not available for energy. The primary ketone bodies found in the urine are acetone and beta-hydroxybutyric acid.

The other options are incorrect:

• None of these: This is incorrect as both acetone and beta-hydroxybutyric acid are ketone bodies found in urine.
• Acetone: This is only one of the ketone bodies.
• Beta-hydroxybutyric acid: This is also only one of the ketone bodies.

Answer: hCG (human chorionic gonadotropin) is the hormone specifically produced by the placenta during pregnancy. Its presence in the blood or urine is a strong indicator of pregnancy.

The other options are incorrect:

• TSH (Thyroid-stimulating hormone): Stimulates the thyroid gland to produce thyroid hormones.
• ADH (Anti-diuretic hormone): Regulates water balance in the body.
• GH (Growth hormone): Stimulates growth and cell reproduction.

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Answer: Diabetes insipidus

A specific gravity of less than 1.010 indicates dilute urine. Diabetes insipidus is a condition characterized by the excessive production of dilute urine due to a deficiency in the antidiuretic hormone (ADH) or the kidney’s inability to respond to ADH.

The other options are incorrect:

• None of the above: This is incorrect as diabetes insipidus is the correct answer.
• Diabetes mellitus: This condition is associated with high blood sugar levels and can lead to increased urine output but not necessarily with a specific gravity less than 1.010.
• Diabetic ketoacidosis: This is a serious complication of diabetes characterized by high blood sugar, ketone production, and acidosis. It does not typically lead to a low specific gravity.

Answer: Buffer

A buffer is a solution that resists changes in pH when small amounts of acid or base are added to it. It does this by neutralizing small amounts of added acid or base, thus preventing radical shifts in pH.

The other options are incorrect:

• Acids: Adding an acid would actually increase the acidity of the solution, potentially leading to a radical shift in pH.
• Alkali: Adding an alkali would increase the alkalinity of the solution, potentially leading to a radical shift in pH.
• None of these: This is incorrect as a buffer is specifically designed to prevent pH shifts.