Biochemistry MCQs with Answer and Explanations | Chapter 3

Answer: All of the above

Magnesium ions (Mg²⁺) play a crucial role in many biological processes, including:

• Stimulating enzyme systems: Over 300 enzymes require magnesium ions for their proper function. These enzymes are involved in various processes like energy production, protein synthesis, and DNA/RNA replication.
• Muscular contraction: Magnesium is essential for muscle relaxation and contraction. It helps regulate the flow of calcium ions, which are critical for muscle function.
• Nerve conduction: Magnesium plays a role in maintaining the electrical balance across nerve membranes, which is necessary for proper nerve impulse transmission.

Answer : Intravenous calcium gluconate

Tetany is a condition caused by low blood calcium levels. Calcium gluconate is an intravenous medication that directly replaces calcium in the bloodstream, effectively controlling the symptoms of tetany.

The other options are incorrect:

• Intravenous diazepam: While diazepam is a muscle relaxant, it doesn’t directly address the underlying calcium deficiency in tetany. It might be used to manage muscle spasms associated with tetany but wouldn’t be the primary treatment.
• Intramuscular vitamin D: Vitamin D is crucial for calcium absorption in the long term, but its effects are slower and wouldn’t be suitable for immediate tetany control.
• Intravenous calcitonin: Calcitonin is a hormone that lowers blood calcium levels. It would be counterproductive in tetany, where the goal is to increase calcium.

Answer: Ascorbic acid

Ascorbic acid (vitamin C) helps convert ferric iron (Fe³⁺) from oral iron supplements into ferrous iron (Fe²⁺). Ferrous iron is more readily absorbed by the intestines.

The other options are incorrect:

• Antacids: Antacids, which often contain calcium or magnesium, can actually hinder iron absorption by forming insoluble complexes with iron.
• Tetracyclines: Tetracyclines are antibiotics that can chelate (bind) iron, reducing its absorption.
• Phosphates: While some studies suggest a possible interaction with iron absorption, phosphates generally don’t significantly improve iron absorption.

Answer: Complexing excess iron to form ferritin which remains stored in the mucosal cell and is shed off

The gut controls the entry of ingested iron into the body primarily by converting excess iron into ferritin within the mucosal cells. Ferritin acts as a storage form of iron, and this stored iron is lost when the mucosal cells are naturally shed and replaced. This mechanism prevents the overload of iron in the body and maintains iron homeostasis.

The other options are incorrect:

• Regulating the availability of apoferritin which acts as the carrier of iron across the mucosal cell: Apoferritin is the protein shell that combines with iron to form ferritin, but it is not directly involved in the transport of iron across the mucosal cell.
• Regulating the turnover of apoferritin-ferritin interconversion in the mucosal cell: While the interconversion between apoferritin and ferritin occurs, this process itself is not the primary method for controlling iron entry into the body. It is more about iron storage within cells.
• Regulating the number of transferrin receptors on the mucosal cell: Transferrin receptors are primarily involved in the uptake of iron from transferrin in the bloodstream into cells, not directly in the absorption of dietary iron through the gut mucosa.

Answer: 20%

Hydrated ferrous sulfate contains approximately 20% elemental iron. This means that out of the total weight of the compound, 20% is pure iron, which is available for absorption by the body.

The other options are incorrect:

• 5%: This percentage is significantly lower than the actual content of elemental iron in hydrated ferrous sulfate.
• 10%: This value is also below the actual content. Hydrated ferrous sulfate provides more elemental iron than this percentage.
• 33%: This value is higher than the actual content of elemental iron in hydrated ferrous sulfate. This percentage is more representative of anhydrous ferrous sulfate.

Answer: Epigastric pain and bowel upset

Epigastric pain refers to discomfort in the upper middle abdomen, and bowel upset can include constipation, nausea, diarrhea, or cramping. These gastrointestinal (GI) side effects are the most common and bothersome for many people taking oral iron supplements, often leading to decreased adherence to treatment.

The other options are incorrect:

• Black stools: While black stools are a common side effect of oral iron, they are usually harmless and don’t cause significant discomfort. Patients can be informed about this beforehand to avoid unnecessary worry.
• Staining of teeth: Iron supplements can stain teeth, but this is generally considered a cosmetic issue and less likely to significantly impact treatment adherence compared to GI discomfort.
• Metallic taste: Metallic taste can be unpleasant but is usually tolerated better than severe GI side effects.

Answer: It cannot be injected i.v.

Iron sorbitol-citric acid complex is typically administered via intramuscular injection and is not suitable for intravenous administration due to its formulation. In contrast, iron dextran can be administered both intramuscularly and intravenously.

The other options are incorrect:

• It is not excreted in urine: Both iron sorbitol-citric acid and iron dextran are metabolized similarly, and iron is primarily excreted via feces, not urine. This statement does not distinctly differentiate between the two.
• It is not bound to transferritin in plasma: Both forms of iron, once released from their complexes, bind to transferritin in plasma for transport to various tissues. This statement is incorrect for both.
• It produces fewer side effects: Both iron sorbitol-citric acid and iron dextran can produce side effects, and the side effect profile varies among individuals. There is no consistent evidence that one produces significantly fewer side effects than the other.

Answer: 100

Concentrations of retinal (vitamin A) in plasma exceeding 100 µg/dl are typically indicative of hypervitaminosis A. This condition results from excessive intake of vitamin A, leading to toxicity and a range of clinical symptoms.

The other options are incorrect

• 10 µg/dl: This concentration is within the normal range for plasma retinal levels and is not indicative of hypervitaminosis A.
• 50 µg/dl: This level is also within the normal range for plasma retinal and does not suggest vitamin A toxicity.
• 200 µg/dl: While this concentration certainly indicates hypervitaminosis A, levels indicative of toxicity are already present at 100 µg/dl, so this answer is higher than the threshold generally used for diagnosis.

Answer: Prophylactic iron therapy must be given during pregnancy

Prophylactic iron therapy is recommended during pregnancy to prevent iron deficiency anemia, which can occur due to the increased iron demands of the growing fetus and placenta, as well as the expanded maternal blood volume.

The other options are incorrect:

• Haemoglobin response to intramuscular iron is faster than with oral iron therapy: While intramuscular iron can be an effective treatment, the response time for hemoglobin increase is generally similar to that of oral iron therapy. Intravenous iron, however, can provide a faster response compared to both.
• Iron must be given orally except in pernicious anaemia: Pernicious anemia is due to vitamin B12 deficiency, not iron deficiency. Iron can be administered orally or parenterally (intravenous or intramuscular) in various conditions depending on the patient’s needs and absorption capacity.
• Infants on breastfeeding do not require medicinal iron: While breast milk contains some iron, it may not be sufficient for the growing infant after the first 4-6 months of life, especially if the infant is at risk for iron deficiency. Supplemental iron might be necessary depending on the infant’s overall health and diet.

Answer: Blackening of the stool

Patients receiving iron therapy should be informed about the side effect of blackening of the stool, which is a harmless and expected occurrence due to the unabsorbed iron reacting with sulfur compounds in the intestines.

The other options are incorrect:

• Dizziness and ringing in the ears: These are not typical side effects of iron therapy. If a patient experiences them, it’s important to consult a doctor to determine the cause.
• Danger of sunlight: Iron therapy doesn’t typically increase sun sensitivity. Sun protection is still important for overall health.

Answer: 1-3 µg

The daily dietary requirement of Vitamin B12 (cobalamin) for an adult is typically 1-3 micrograms (µg). Vitamin B12 is essential for the normal functioning of the nervous system, DNA synthesis, and red blood cell formation.

The other options are incorrect:

• 50-100 µg: This range is significantly higher than the daily requirement for Vitamin B12. Such doses might be used in therapeutic settings or for individuals with specific medical conditions but are not representative of normal dietary requirements.
• 0.1-0.5 µg: This range is too low and would not meet the daily dietary requirement for Vitamin B12. Insufficient intake can lead to deficiency symptoms over time.
• 5-10 µg: This range is higher than the typically recommended daily requirement for Vitamin B12. While intake within this range is generally safe, it exceeds the average daily dietary need for most adults.

Answer: Both (Gastric acid) and ( Gastric intrinsic factor)

The absorption of Vitamin B12 requires both gastric acid (hydrochloric acid) and gastric intrinsic factor. Gastric acid helps to release Vitamin B12 from dietary proteins, and gastric intrinsic factor, produced by parietal cells in the stomach, binds to Vitamin B12 to facilitate its absorption in the ileum of the small intestine.

The other options are incorrect:

• Gastric acid: Gastric acid alone is not sufficient for Vitamin B12 absorption. While it aids in the release of Vitamin B12 from dietary proteins, the presence of intrinsic factor is necessary for its absorption in the intestines.
• Gastric intrinsic factor: Intrinsic factor alone is not enough for Vitamin B12 absorption. While it binds to Vitamin B12 and forms a complex that can be recognized by receptors in the ileum, gastric acid is also required for the initial steps of absorption.
• Transcobalamin: Transcobalamin is a transport protein that binds Vitamin B12 in the bloodstream after absorption. It does not play a role in the initial absorption of Vitamin B12 from the gastrointestinal tract.

Answer: Both (It is more protein bound and better retained) and (It is beneficial in tobacco amblyopia)

Hydroxocobalamin differs from cyanocobalamin in that it is more protein-bound and better retained in the body. This means it has a longer half-life and can be stored more effectively in tissues. Additionally, hydroxocobalamin has been found to be beneficial in treating tobacco amblyopia (visual impairment due to tobacco use), possibly due to its longer duration of action compared to cyanocobalamin.

The other options are incorrect:

• It is more protein bound and better retained: This statement is actually correct and describes one of the differences between hydroxocobalamin and cyanocobalamin. Hydroxocobalamin binds more strongly to proteins and is retained in the body for a longer period compared to cyanocobalamin.
• It is beneficial in tobacco amblyopia: This statement is also correct. Hydroxocobalamin has shown efficacy in improving visual impairment associated with tobacco use (tobacco amblyopia), likely due to its unique properties and longer duration of action.
• It benefits hematological but not neurological manifestations of Vit B12 deficiency: This statement is incorrect. Hydroxocobalamin is effective in treating both hematological (blood-related) and neurological manifestations of Vitamin B12 deficiency. It is not limited to only one type of symptom manifestation.

Answer: Vitamin B12

Megaloblastic anemia is primarily caused by a deficiency of Vitamin B12 (cobalamin) or folate (Vitamin B9). These vitamins are essential for DNA synthesis and red blood cell maturation. Without adequate Vitamin B12, red blood cells become larger than normal (megaloblastic), but they are unable to function properly, leading to anemia.

The other options are incorrect:

• Iron: Iron deficiency leads to a different type of anemia called microcytic anemia, characterized by small, pale red blood cells.
• Vitamin C: While vitamin C plays a role in overall health, it’s not directly involved in DNA synthesis and typically wouldn’t cause megaloblastic anemia on its own.
• All of the above: Although both B12 and folate deficiencies are common causes, iron and vitamin C deficiency wouldn’t typically cause megaloblastic anemia.

Answer: All of the above

Vitamin B12 acts as a co-factor for several important enzymatic reactions in the body. Here’s why each option is a valid function of vitamin B12:

• Conversion of methylmalonyl-CoA to succinyl-CoA: This reaction is part of the propionic acid metabolism pathway. Vitamin B12 deficiency can lead to the accumulation of methylmalonic acid, a marker for B12 deficiency.
• Conversion of 5-CH3-H4-folate (methylfolate) to H4-folate (folate): This reaction is crucial for folate recycling and maintaining sufficient folate levels for other important processes.
• Conversion of homocysteine to methionine: This reaction plays a vital role in amino acid metabolism and methylation, a process involved in DNA synthesis, gene expression, and nervous system function. Vitamin B12 deficiency can lead to elevated homocysteine levels.

Answer: Can cause hemolysis in patients with G-6-PD deficiency

Menadione (Vitamin K3) can cause hemolysis (destruction of red blood cells) in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. This is due to its oxidative properties, which can lead to the formation of reactive oxygen species that damage red blood cells in individuals with this enzyme deficiency.

The other options are incorrect:

• Is given in large doses in patients with severe liver disease: Menadione is not typically used in large doses in patients with severe liver disease. In such cases, Vitamin K1 (phytonadione) is preferred due to its greater safety profile and effectiveness in treating clotting disorders associated with liver disease.
• Is useful to prevent hemorrhagic disease of the newborn: Menadione is not recommended for the prevention of hemorrhagic disease of the newborn (HDN). Instead, Vitamin K1 is administered to newborns shortly after birth to prevent bleeding complications due to Vitamin K deficiency.
• Is the preparation of choice to antagonize the effect of warfarin overdose: Menadione (Vitamin K3) is not used as the preparation of choice to antagonize the effect of warfarin overdose. Vitamin K1 (phytonadione) is the preferred form for this purpose, as it effectively reverses the anticoagulant effects of warfarin.

Answer: Factor II

Vitamin K promotes the hepatic biosynthesis of Factor II, also known as prothrombin. Prothrombin is a key clotting factor involved in the coagulation cascade, essential for the formation of blood clots.

The other options are incorrect:

• Factor I: Factor I, also known as fibrinogen, is not directly synthesized in the liver under the influence of Vitamin K. Fibrinogen is involved in the final step of blood clot formation, where it is converted to fibrin.
• Factor VIII: Factor VIII is another clotting factor, but it is not synthesized in the liver under the influence of Vitamin K. Factor VIII is synthesized in endothelial cells and is essential for blood clotting, specifically in the intrinsic pathway.
• All of the above: While Vitamin K does promote the synthesis of clotting factors, it specifically promotes the synthesis of Factors II, VII, IX, and X. Factor VIII is not synthesized under the influence of Vitamin K, and Factor I (fibrinogen) is also not directly synthesized in the liver under the influence of Vitamin K.

Answer: Along with methotrexate therapy

Folinic acid (also known as leucovorin) is principally used along with methotrexate therapy. Methotrexate is an anti-folate medication that inhibits dihydrofolate reductase, leading to decreased folate levels. Folinic acid is given to rescue normal cells from the toxic effects of methotrexate without rescuing cancer cells.

The other options are incorrect:

• In pernicious anaemia: Pernicious anemia is caused by Vitamin B12 deficiency, not folate deficiency. Folinic acid is not effective in treating pernicious anemia; Vitamin B12 supplementation is required.
• In megaloblastic anaemia secondary to Vitamin B12: Megaloblastic anemia due to Vitamin B12 deficiency is treated with Vitamin B12 (cyanocobalamin or hydroxocobalamin) and not with folinic acid. Folinic acid is used for folate deficiency anemia.
• In treatment of folic acid deficiency: Folinic acid is a form of folate, but it is not typically used for treating straightforward folic acid deficiency. Instead, folic acid (Vitamin B9) supplementation is used to treat folate deficiency anemia.

Answer: Can cause anaphylactic reactions in patients allergic to penicillin

Penicillamine can cause anaphylactic reactions in patients who are allergic to penicillin. Despite its name, penicillamine is not structurally related to penicillin but can still trigger severe allergic reactions in individuals with penicillin allergies.

The other options are incorrect:

• Is effective orally: As mentioned earlier, penicillamine is indeed effective when taken orally.
• Is safe in pregnancy: Penicillamine can be harmful to a developing fetus, so it’s not considered safe during pregnancy.
• Is not effective in lead poisoning: Penicillamine is a well-established treatment for lead poisoning.

Answer: Produces less toxicity than Dimercaprol

Succimer produces less toxicity than Dimercaprol. Succimer (Dimercaptosuccinic acid or DMSA) is an oral chelating agent used to treat heavy metal poisoning, particularly lead poisoning in children. It has a lower toxicity profile compared to Dimercaprol (BAL), which is administered intramuscularly and has more significant side effects.

The other options are incorrect:

• Can significantly mobilize essential metals: Succimer primarily chelates heavy metals such as lead, mercury, and arsenic. It is not known for significantly mobilizing essential metals like iron, zinc, or copper.
• Is ineffective orally: Succimer is effective when administered orally. It is well-absorbed from the gastrointestinal tract and is used to treat lead poisoning in children by facilitating the excretion of lead through urine.
• Is contraindicated in children: Succimer is actually indicated for use in children, particularly for the treatment of lead poisoning. It is considered safer and easier to administer compared to other chelating agents like Dimercaprol.

Answer: Ferritin

Ferritin is the major metabolically available storage form of iron in the body. It’s a protein complex that can safely store large amounts of iron within cells, particularly in the liver, spleen, and bone marrow. Ferritin acts as a reservoir, releasing iron when the body needs it and taking up excess iron for storage when levels are high.

The other options are incorrect:

• Hemosiderin: While also a form of iron storage, hemosiderin is an insoluble aggregate that forms when excess iron overwhelms ferritin’s storage capacity. It’s less readily available for metabolic use compared to ferritin.
• Transferrin: Transferrin is a transport protein in the blood that carries iron throughout the body. It doesn’t store iron but delivers it to cells that need it.
• Hemoglobin: Hemoglobin is the major iron-containing protein in red blood cells, responsible for oxygen transport. It’s not a storage form of iron and constantly undergoes turnover as red blood cells are recycled.

Answer: No neurological symptoms in folic acid

One of the key differences between Vitamin B12 deficiency and folate (Vitamin B9) deficiency is that folate deficiency does not typically cause neurological symptoms. Neurological symptoms such as peripheral neuropathy, paresthesia (tingling sensation), and cognitive disturbances are characteristic of Vitamin B12 deficiency but are not seen with folate deficiency alone.

The other options are incorrect:

• Glossitis: Glossitis (inflammation of the tongue) can occur in both Vitamin B12 and folate deficiencies. It is a common symptom due to impaired DNA synthesis affecting rapidly dividing cells in the mucosa.
• Muscle wasting: Muscle wasting (atrophy) can occur in severe cases of both Vitamin B12 and folate deficiencies. It is a consequence of impaired protein synthesis and neurological dysfunction.
• Dizziness: Dizziness can occur in both Vitamin B12 and folate deficiencies, especially if anemia is present. Anemia leads to decreased oxygen delivery to the brain, resulting in symptoms like dizziness and fatigue.

Answer: False

Folic acid therapy does not cause sickle cell anemia. Sickle cell anemia is a genetic disorder characterized by abnormal hemoglobin molecules that cause red blood cells to become rigid and crescent-shaped. Folic acid supplementation is often prescribed for individuals with sickle cell disease to support red blood cell production and overall health, but it does not cause the disease itself.

• True: Folic acid therapy does not cause sickle cell anemia. Sickle cell anemia is caused by genetic factors affecting hemoglobin structure, not by folic acid supplementation.
• Equal: This option doesn’t apply in this context as it seems to suggest a comparison or equivalence between different statements. It does not provide a meaningful response to the question.
• All are above: None of the statements above are true. Folic acid therapy does not cause sickle cell anemia, and the options provided do not correctly answer the question posed.

Answer: PPI, H2 blockers

PPI (Proton Pump Inhibitors) and H2 blockers: These medications reduce stomach acid production. This can decrease the absorption of both iron and vitamin B12, potentially leading to deficiencies if taken long-term or at high doses.

The other options are incorrect:

• Methyldopa: While some studies suggest possible interactions between methyldopa and vitamin B12 absorption, it’s not a well-established concern for most individuals.
• Metformin: Metformin, a medication used for diabetes, doesn’t typically interfere with the absorption of either vitamin B12 or iron.

Answer : True

Hydroxyurea is a chemotherapy medication used to treat various conditions, including sickle cell anemia. One of its side effects is an increase in serum uric acid levels. This can potentially lead to gout or uric acid nephropathy if not monitored and managed appropriately.

The other options are incorrect:

• False: Hydroxyurea has been documented to elevate serum uric acid levels.

Answer: All of the above

Hypocupremia, or low copper levels in the blood, can occur in various conditions:

• Osteoporosis, nephrotic syndrome: These conditions can lead to increased copper loss through the urine or intestines, contributing to deficiency.
• Sprue, celiac disease: These are malabsorption disorders that can impair copper absorption from food.
• Cardiovascular disease, colon cancer: While less common, chronic inflammatory conditions like these can sometimes be associated with copper deficiency, possibly due to altered copper metabolism or dietary factors.

Answer: False

Antimalarial drugs and high-dose birth control pills do not increase riboflavin (Vitamin B2) levels. In fact, certain medications, including antimalarials and hormonal contraceptives, can interfere with the absorption or metabolism of vitamins and minerals, potentially leading to deficiencies rather than increases in their levels.

The other options are incorrect: True: Antimalarial drugs and high-dose birth control pills do not increase riboflavin levels. Instead, they may interfere with the absorption or utilization of riboflavin and other nutrients.

Answer: acid phosphatase

Acid phosphatase is the enzyme most commonly estimated in semen analysis to assess the secretory function of the prostate gland. The prostate gland is a major contributor to seminal fluid, and acid phosphatase is a specific enzyme produced in high concentrations by the prostate.

The other options are incorrect:

• Alanine transaminase (ALT): ALT is a liver enzyme primarily used to assess liver function. It is not specific to the prostate gland and is not measured in semen analysis.
• Aspartate transaminase (AST): AST is another liver enzyme used to assess liver function and is not specific to the prostate gland or semen analysis.
• Alkaline phosphatase: While this enzyme is present in semen, it’s not specific to the prostate and can come from other sources like the seminal vesicles.

Answer: Hays test

The Hays test is a simple and commonly used test to detect bile salts in urine. It relies on the ability of bile salts to lower the surface tension of the urine. When sulfur powder is sprinkled on the surface of urine, it will typically float if bile salts are absent. However, in the presence of bile salts, the surface tension is reduced, causing the sulfur powder to sink.

The other options are incorrect:

• Benzidine test: This test is no longer recommended due to its carcinogenicity.
• Fouchet’s test: Fouchet’s test is used to detect the presence of bilirubin in urine, which can indicate liver disease or other conditions affecting the liver’s ability to process bilirubin. It is not specific for bile salts.
• Ehrlich’s test: Ehrlich’s test is used to detect the presence of urobilinogen in urine, which is a breakdown product of bilirubin. It is not specific for bile salts.

Answer: Both acetone and ‘beta’ hydroxy butyric acid

Ketone bodies present in urine include acetone and ‘beta’ hydroxy butyric acid. These are metabolic by-products produced when the body breaks down fat for energy in the absence of sufficient carbohydrates or when there is impaired carbohydrate metabolism (such as in diabetes mellitus). Elevated ketone levels in urine can indicate metabolic conditions like diabetic ketoacidosis or starvation.

The other options are incorrect:

• Acetone: Acetone is indeed a ketone body that can be detected in urine, particularly in individuals undergoing ketosis (such as in diabetes or during fasting).
• ‘Beta’ hydroxy butyric acid: ‘Beta’ hydroxy butyric acid is another ketone body found in urine. It is produced during ketosis and is an important energy source when glucose availability is limited.
• None of these: This option is incorrect because both acetone and ‘beta’ hydroxy butyric acid are ketone bodies that can be detected in urine. They are commonly measured in clinical settings to assess metabolic status, particularly in diabetic patients or those on ketogenic diets.

Answer: hCG

hCG is the hormone typically detected in pregnancy tests. It’s produced by the placenta shortly after implantation of a fertilized egg in the uterus. hCG levels rise rapidly in early pregnancy and are used to confirm pregnancy and assess its viability.

The other options are incorrect:

• ADH (Antidiuretic hormone): While ADH plays a role in regulating water balance, it’s not specifically associated with pregnancy detection.
• GH (Growth hormone): GH levels might fluctuate during pregnancy, but it’s not the primary hormone detected for pregnancy testing.
• TSH (Thyroid-stimulating hormone): TSH levels can be affected by pregnancy, but it’s not routinely measured for pregnancy detection.

Answer: Diabetes insipidus

A specific gravity of urine less than 1.010 typically indicates diabetes insipidus. Diabetes insipidus is a condition characterized by excessive thirst and excretion of large amounts of diluted urine, caused by either a deficiency of antidiuretic hormone (ADH) or resistance to its effects.

The other options are incorrect:

• Diabetes mellitus: Diabetes mellitus is a condition characterized by elevated blood sugar levels due to insufficient insulin production or insulin resistance. It does not typically cause urine with a specific gravity less than 1.010; instead, it often leads to increased urine output with elevated specific gravity.
• Diabetic ketoacidosis: Diabetic ketoacidosis is a serious complication of diabetes mellitus, usually type 1 diabetes, where there is a buildup of ketones in the blood and urine due to insufficient insulin. It does not typically cause urine with a specific gravity less than 1.010; rather, urine specific gravity may be elevated due to dehydration.

Answer: HbA1C

The “glucose memory test” refers to the HbA1C test (Hemoglobin A1C). This test measures the average blood sugar (glucose) levels over the past two to three months by assessing the amount of glucose bound to hemoglobin in red blood cells. It is used to monitor long-term glucose control in individuals with diabetes mellitus.

The other options are incorrect:

• GCT (Glucose Challenge Test): The Glucose Challenge Test (GCT) is used to screen for gestational diabetes during pregnancy. It involves drinking a glucose solution followed by blood tests to measure glucose levels at specific intervals.
• GTT (Glucose Tolerance Test): The Glucose Tolerance Test (GTT) is used to diagnose diabetes mellitus or gestational diabetes. It involves fasting overnight and then drinking a concentrated glucose solution followed by multiple blood tests to measure how the body processes glucose over time.
• PPBS (Postprandial Blood Sugar): Postprandial Blood Sugar (PPBS) refers to blood sugar levels measured after eating (post-meal). It is used to assess glucose levels two hours after consuming a meal and is part of the diagnostic criteria for diabetes mellitus.

Answer: Total cholesterol

Total cholesterol is not a renal function test. It is a blood test used to measure the total amount of cholesterol in the blood, which is important for assessing cardiovascular health and risk factors for heart disease.

The other options are incorrect:

• Serum urea: Serum urea, or blood urea nitrogen (BUN), is a commonly used test to assess kidney function. It measures the amount of urea nitrogen in the blood, which is a waste product filtered by the kidneys.
• Serum creatinine: Serum creatinine is another important test for evaluating kidney function. Creatinine is a waste product of muscle metabolism that is filtered out of the blood by the kidneys. Elevated levels can indicate impaired kidney function.
• Cystatin-C: Cystatin-C is a newer marker used to estimate kidney function, particularly in situations where creatinine levels may not accurately reflect kidney function, such as in elderly individuals or those with reduced muscle mass.

Answer: Factors V & VIII

Factors V & VIII are not stable at low freezing points. These coagulation factors are heat-labile and can be easily denatured when exposed to extreme temperatures, including freezing. Therefore, their activity can be significantly reduced or lost when subjected to freezing temperatures.

The other options are incorrect:

1. Factors IX & X: Factors IX & X are stable at low freezing points. They are not as sensitive to temperature changes and remain functional under freezing conditions.
2. Factors IV & V: Factors IV & V are not typically discussed in the context of coagulation factors. Factor IV is actually calcium, which is essential for the coagulation cascade, and its stability is not related to freezing temperatures. Factor V is heat-labile but not included in the correct answer.
3. Factors II: Factor II (prothrombin) is stable at low freezing points. It is an essential coagulation factor that is converted to thrombin during the coagulation cascade and remains functional under freezing conditions.

Answer: Flamephotometer

Serum electrolytes are typically analyzed using a flame photometer. A flame photometer is a device used to measure the concentration of certain elements, including sodium, potassium, and calcium, based on the intensity of light emitted when the ions are exposed to a flame. The intensity of the emitted light is proportional to the concentration of the element being measured.

The other options are incorrect:

• Calorimeter: Calorimeters measure heat flow or change in temperature. While they have various applications, they are not typically used for routine electrolyte analysis.
• Spectrophotometer: Spectrophotometers can be used for various analyses, but for electrolytes, flame photometry is often preferred due to its simplicity, speed, and cost-effectiveness. Some specific electrolytes might be measured using spectrophotometry in some labs.
• None of the above: While other techniques might be used in some research settings, flame photometry remains a widely used and rel

Answer: Serum bilirubin

The Van-den-Bergh reaction is a chemical test used to measure the amount and type of bilirubin in the blood. Bilirubin is a yellow pigment produced by the breakdown of red blood cells.

The other options are incorrect:

• Serum creatinine: Serum creatinine levels are typically measured using methods like the Jaffe reaction or enzymatic assays, not the Van-den-Bergh reaction.
• Serum urea: Serum urea levels are usually measured using the urease method or the Berthelot reaction, not the Van-den-Bergh reaction.
• Blood glucose: Blood glucose levels are measured to assess diabetes and are not related to bilirubin levels.

Answer: Tuberculous meningitis

The cob-web appearance of clot in cerebrospinal fluid (CSF) is characteristic of tuberculous meningitis. This appearance is due to the formation of fine fibrinous strands within the CSF, which can be observed during microscopic examination of CSF samples from patients with tuberculous meningitis.

The other options are incorrect:

• Jaundice: Jaundice is characterized by yellowing of the skin and mucous membranes due to elevated bilirubin levels in the blood. It is not associated with the cob-web appearance of clot in CSF.
• Haemorrhage: Haemorrhage refers to bleeding, which can occur in various tissues or organs, including the brain. It does not cause a cob-web appearance of clot in CSF.
• Spinal constriction: Spinal constriction (or spinal cord compression) can result from various causes, such as trauma or tumors compressing the spinal cord. It is not associated with the cob-web appearance of clot in CSF.

Answer: LDL

LDL (low-density lipoprotein) is often referred to as “bad cholesterol” because high LDL levels contribute to the buildup of plaque in arteries. This plaque buildup can narrow the arteries and increase the risk of heart disease and stroke.

The other options are incorrect:

• HDL (high-density lipoprotein): HDL is known as “good cholesterol” because it helps remove LDL cholesterol from the arteries and transport it back to the liver for breakdown.
• VLDL (very-low-density lipoprotein): VLDL carries triglycerides, a type of fat, from the liver to other parts of the body. High VLDL levels can also contribute to heart disease.
• Chylomicrons: These are large lipoproteins that transport dietary fat from the intestines to the body’s tissues. Similar to VLDL, high chylomicron levels can be a risk factor for heart disease.

Answer: amylase

Amylase is the enzyme estimation done for the diagnosis of pancreatitis. During pancreatitis, the pancreas becomes inflamed, leading to the leakage of pancreatic enzymes, including amylase, into the bloodstream. Elevated levels of serum or urine amylase are indicative of pancreatitis and are used in the diagnosis and monitoring of this condition.

The other options are incorrect:

• Acid phosphatase: Acid phosphatase is an enzyme found in various tissues, including the prostate gland and red blood cells. It is not specific for pancreatitis and is not used in the diagnosis of this condition.
• Alkaline phosphatase: Alkaline phosphatase is an enzyme found in various tissues, including the liver, bones, kidneys, and intestines. Elevated levels can indicate liver or bone disease, but it is not specific for pancreatitis.
• Creatinine kinase: Creatinine kinase (CK), also known as creatine phosphokinase (CPK), is an enzyme found predominantly in skeletal muscle, heart muscle, and brain tissue. Elevated levels can indicate muscle damage but are not specific for pancreatitis.

Answer: H202

Hydrogen peroxide (H2O2) is not a flammable chemical. It is an oxidizing agent and can decompose exothermically, but it is not considered flammable under normal conditions.]

The other options are incorrect:

• Ether: Ether is highly flammable. It has a low flash point and can easily form explosive peroxides when exposed to air. Special precautions are required when handling ether due to its flammability.
• Xylol (Xylene): Xylene is a flammable liquid with a relatively low flash point. It is commonly used as a solvent and requires handling and storage precautions to prevent fire hazards.
• Alcohol (Ethanol, Isopropanol, etc.): Alcohol, such as ethanol and isopropanol, are flammable liquids. They have low flash points and can ignite easily under certain conditions. Proper ventilation and handling are essential to prevent fire risks when using alcohol in laboratories or industrial settings.

Answer: Rothera’s test

Rothera’s test is a simple and qualitative test used to detect the presence of ketone bodies (acetone, acetoacetic acid, and beta-hydroxybutyric acid) in urine.

The other options are incorrect:

• Diazo test: This test is used to detect bilirubin in urine, not ketone bodies.
• Benzidine test: This test was previously used for blood but is no longer recommended due to its carcinogenicity. It’s not specific for ketone bodies.
• Ehrlich’s test: This test is used to detect bilirubin in urine or other bodily fluids, not ketone bodies.

Answer: Multiple myeloma

Bence-Jones protein is a monoclonal immunoglobulin light chain or fragment found in the urine of patients with multiple myeloma. It can be detected through urine protein electrophoresis or immunofixation electrophoresis. The presence of Bence-Jones protein in urine is a hallmark feature of multiple myeloma, a malignant plasma cell disorder.

The other options are incorrect:

• Acute myeloid leukemia (AML): This is a cancer of the bone marrow that affects immature blood cells, not specifically plasma cells. While some proteins might be abnormal in AML, Bence-Jones proteins are not a typical feature.
• Malignant lymphoma: Lymphomas are cancers of the lymphatic system, and while some lymphomas might involve plasma cells, Bence-Jones proteins are not as common in all types of lymphomas compared to multiple myeloma.
• Chronic myeloid leukemia (CML): Similar to AML, CML affects immature myeloid cells in the bone marrow and doesn’t typically cause Bence-Jones protein production.

Answer: Protein Electrophorosis

CSF (Cerebrospinal Fluid) protein fractions are typically evaluated using Protein Electrophoresis. This method separates proteins based on their charge and size using an electric field. It provides a detailed analysis of different protein fractions present in CSF, including albumin, globulins, and other proteins. Protein electrophoresis is an important diagnostic tool in assessing various neurological disorders that affect CSF protein levels.

The other options are incorrect:

1. Colloidal gold test: The colloidal gold test is used for the qualitative detection of proteins in CSF. It involves the aggregation of gold particles in the presence of proteins. It is not used for the quantitative evaluation of protein fractions in CSF.
2. Pandy’s test: Pandy’s test is used to detect the presence of globulins in CSF. It involves the addition of a few drops of acetic acid to CSF, followed by the addition of a few drops of concentrated sulfuric acid. A white precipitate indicates the presence of globulins. It is not used for the quantitative evaluation of protein fractions in CSF.
3. Rose Jone’s test: Rose Jone’s test is used to evaluate the protein concentration in CSF by precipitating proteins with trichloroacetic acid (TCA) and analyzing the supernatant. It is used for qualitative estimation and does not provide a detailed fractionation of protein types like protein electrophoresis does.

Answer: 10 weeks of gestation

In pregnancy, the peak level of hCG (human chorionic gonadotropin) in urine is typically seen around 10 weeks of gestation. hCG is a hormone produced by the placenta early in pregnancy, and its levels rise rapidly in the first trimester. After reaching peak levels around 10 weeks, hCG concentrations gradually decline.

The other options are incorrect:

• 4 weeks of gestation: At 4 weeks of gestation, hCG levels in urine are detectable but typically not at peak levels. Levels may still be relatively low early in pregnancy.
• 6 weeks of gestation: At 6 weeks of gestation, hCG levels in urine are increasing but may not have reached peak levels yet. The rise in hCG during early pregnancy is progressive.
• 14 weeks of gestation: By 14 weeks of gestation, hCG levels in urine have generally decreased from their peak levels seen around 10 weeks. hCG is still present but at lower concentrations compared to earlier stages of pregnancy.

Answer: 70-110 mg/dl

The normal fasting blood glucose level is typically considered to be in the range of 70-110 mg/dl (milligrams per deciliter). This range may vary slightly depending on the laboratory and specific guidelines, but generally, fasting blood glucose levels within this range are considered normal.

The other options are incorrect:

1. 50-80 mg/dl: This range is lower than the typical normal fasting blood glucose level. Blood glucose levels in this range may indicate hypoglycemia (low blood sugar), which can be clinically significant and may require medical attention.
2. 120-160 mg/dl: This range is higher than the typical normal fasting blood glucose level. Blood glucose levels in this range may indicate hyperglycemia (high blood sugar), which can be associated with conditions like diabetes mellitus.
3. 180-220 mg/dl: This range is significantly higher than the typical normal fasting blood glucose level. Blood glucose levels in this range are indicative of hyperglycemia and may be seen in uncontrolled diabetes mellitus or other medical conditions affecting glucose metabolism.

Answer: Flamephotometer

Serum electrolytes are analyzed using a flame photometer. A flame photometer is an instrument that measures the intensity of light emitted by the flame when elements such as sodium, potassium, calcium, and lithium in the sample emit light at characteristic wavelengths. This method is particularly suited for the rapid analysis of electrolytes in clinical laboratories.

The other options are incorrect:

• Calorimeter: A calorimeter is used to measure the heat of a reaction or the heat capacity of substances. It is not used for the analysis of serum electrolytes.
• Spectrophotometer: A spectrophotometer is used to measure the absorbance or transmission of light by a substance at different wavelengths. While spectrophotometry is widely used in clinical laboratories for various tests, it is not typically used for routine serum electrolyte analysis.

Answer: Serum bilirubin

The Van-den-Bergh reaction is a chemical test used to measure the amount and type of bilirubin in the blood. Bilirubin is a yellow pigment produced by the breakdown of red blood cells.

The other options are incorrect:

• Serum creatinine and serum urea: These are waste products eliminated by the kidneys and are not directly related to bilirubin. They are measured through renal function tests.
• Blood glucose: Blood glucose levels are measured to assess diabetes and are not related to bilirubin levels.

Answer: LDL

LDL (low-density lipoprotein) is often referred to as “bad cholesterol” because high LDL levels contribute to the buildup of plaque in arteries. This plaque buildup can narrow the arteries and increase the risk of heart disease and stroke.

The other options are incorrect:

• HDL (high-density lipoprotein): HDL is known as “good cholesterol” because it helps remove LDL cholesterol from the arteries and transport it back to the liver for breakdown.
• VLDL (very-low-density lipoprotein): VLDL carries triglycerides, a type of fat, from the liver to other parts of the body. High VLDL levels can also contribute to heart disease.
• Chylomicrons: These are large lipoproteins that transport dietary fat from the intestines to the body’s tissues. Similar to VLDL, high chylomicron levels can be a risk factor for heart disease.

Answer: All the above

In obstructive jaundice, caused by a blockage in the bile ducts, several serum enzyme levels can become elevated. Here’s why:

• SGOT (Serum Glutamic Oxaloacetic Transaminase): While not as specific as SGPT for liver damage, levels can increase due to some liver cell injury caused by the obstruction.
• SGPT (Serum Glutamic Pyruvate Transaminase): This enzyme is primarily found in the liver. In obstructive jaundice, damaged liver cells can release SGPT into the bloodstream, leading to elevated levels.
• ALP (Alkaline Phosphatase): This enzyme is produced in the liver, bones, and other tissues. In obstructive jaundice, the blockage in the bile ducts can cause bile salts to back up into the liver, leading to increased ALP production and elevated serum levels.