Veterinary Biochemistry Quiz 28 Quiz InstructionsThis quiz consists of 20 multiple-choice questions.You will be awarded 5 marks for each correct answer. Question 1: Which of the following best explains why alcohol consumption in a starved state leads to acute hypoglycemia?Direct inhibition of glycogen synthase in the liver by acetaldehyde.Accumulation of NADH during ethanol metabolism that diverts pyruvate and oxaloacetate to lactate and malate.Enhanced excretion of free glucose via the kidneys due to decreased renal threshold.Hypersecretion of insulin from pancreatic beta-cells stimulated by acetate. Question 2: Overexpression of which of the following growth factor receptor genes is most specifically associated with breast cancer?erb-B1erb-B2erb-B3sis Question 3: According to the World Health Organization (WHO) criteria, what are the minimum plasma glucose levels required to confirm a diagnosis of diabetes mellitus during an Oral Glucose Tolerance Test (OGTT)?Fasting ≥ 110 mg/dl and 2-hour post-glucose ≥ 140 mg/dlFasting > 126 mg/dl and 2-hour post-glucose > 200 mg/dlFasting > 140 mg/dl and 2-hour post-glucose > 180 mg/dlFasting ≥ 100 mg/dl and 2-hour post-glucose ≥ 126 mg/dl Question 4: What are the respective periods over which glycated hemoglobin (HbA1c) and plasma fructosamine reflect mean glycemic control?HbA1c reflects 1 month; fructosamine reflects 1 week.HbA1c reflects 2 months; fructosamine reflects 3 weeks.HbA1c reflects 3 months; fructosamine reflects 6 weeks.HbA1c reflects 4 months; fructosamine reflects 2 weeks. Question 5: Malignant tumors that originate from connective tissues are medically classified as:CarcinomasAdenomasSarcomasMelanomas Question 6: The Ames assay is a widely used laboratory screening test for identifying mutagenic carcinogens. Which mutant strain of bacterium does this assay utilize?Escherichia coli (Lac-)Salmonella typhimurium (His-)Bacillus subtilis (Met-)Pseudomonas aeruginosa (Trp-) Question 7: Microalbuminuria, a key early clinical indicator of reversible renal damage in diabetic patients, is defined as the daily excretion of albumin in the range of:2.5 to 30 mg/day30 to 300 mg/day300 to 1000 mg/dayMore than 1000 mg/day Question 8: In Burkitt's lymphoma, a cancer of B-lymphocytes, oncogenic activation occurs via a reciprocal chromosomal translocation. Which chromosomes are involved in this translocation, resulting in the activation of the myc gene?Chromosomes 9 and 22Chromosomes 8 and 14Chromosomes 15 and 17Chromosomes 11 and 14 Question 9: What specific genetic alteration occurs in response to cancer chemotherapy with methotrexate, leading to drug resistance due to a massive increase in the target enzyme's activity?Point mutation of thymidylate synthaseGene amplification of dihydrofolate reductaseTranslocation of ribonucleotide reductaseDeletion of methyltetrahydrofolate reductase Question 10: Which of the following clinical tumor markers is specifically elevated in cases of choriocarcinoma?CalcitoninAlpha-fetoproteinHuman chorionic gonadotropinCarcinoembryonic antigen Question 11: Match the following tumor markers (Column I) with their associated primary neoplastic conditions (Column II):I. CA-125II. CalcitoninIII. Prostate-specific antigen (PSA)IV. Bence-Jones proteins1. Medullary thyroid carcinoma2. Multiple myeloma3. Ovarian cancer4. Prostate cancerI-3, II-1, III-4, IV-2I-3, II-4, III-1, IV-2I-2, II-1, III-4, IV-3I-1, II-3, III-2, IV-4 Question 12: Match the classifications of hypoglycemia (Column I) with their corresponding typical causative factors or clinical contexts (Column II):I. Post-prandial hypoglycemiaII. Fasting hypoglycemiaIII. Hypoglycemia due to alcohol intakeIV. Hypoglycemia in premature infants1. Pancreatic beta-cell tumor or hepatocellular damage2. Excessive post-meal insulin secretion3. Decreased stores of hepatic glycogen4. Diverting gluconeogenesis substrates due to elevated NADH levelsI-2, II-1, III-4, IV-3I-2, II-4, III-1, IV-3I-1, II-2, III-3, IV-4I-3, II-1, III-4, IV-2 Question 13: Match the polypeptide growth factors or receptors (Column I) with their source, function, or disease association (Column II):I. ErythropoietinII. Transforming growth factor-alpha (TGF-α)III. erb-B2 gene productIV. Platelet-derived growth factor (PDGF)1. Highly produced in psoriasis; stimulates epithelial cell growth2. Secreted by kidneys; stimulates erythropoietic development3. Contained in platelets; promotes wound healing4. Growth factor receptor associated with stomach cancerI-2, II-1, III-4, IV-3I-2, II-4, III-1, IV-3I-3, II-1, III-4, IV-2I-1, II-2, III-3, IV-4 Question 14: Match the oncogenic viruses (Column I) with their scientific viral classification (Column II):I. Epstein-Barr virusII. Mammary tumor virus of mouseIII. Adenovirus 12IV. Rous Sarcoma virus1. DNA virus: Adenovirus family2. DNA virus: Herpesvirus family3. RNA virus: Retrovirus type B4. RNA virus: Retrovirus type CI-2, II-3, III-1, IV-4I-2, II-1, III-3, IV-4I-1, II-3, III-2, IV-4I-4, II-3, III-1, IV-2 Question 15: Consider the following statements regarding the molecular mechanism of the ras protooncogene and its activation:I. In its inactive state, the ras P21 protein is bound to GDP.II. Cell stimulation by growth factors triggers the exchange of GDP for GTP, catalyzed by Guanine Nucleotide Releasing Factor (GRF).III. The intrinsic GTPase activity of normal ras P21 hydrolyzes GTP to GDP, a process accelerated by GTPase Activating Proteins (GAP).IV. Point mutations in the ras gene result in an altered protein that lacks GTPase activity, rendering it permanently active.Which of these statements are correct?I, II, and III onlyII, III, and IV onlyI and IV onlyI, II, III, and IV Question 16: Analyze the following biochemical and clinical comparisons between IDDM (Type I) and NIDDM (Type II) diabetes mellitus:I. Ketosis is a very common feature in IDDM, but is rare in NIDDM.II. Plasma insulin levels are decreased or absent in IDDM, whereas they can be normal or even increased in NIDDM.III. Autoantibodies are frequently detected at diagnosis in patients with NIDDM, but are rare in IDDM.IV. The primary acute complication of IDDM is ketoacidosis, whereas NIDDM is more commonly associated with hyperosmolar coma.Which of the statements are correct?I, II, and III onlyI, II, and IV onlyII, III, and IV onlyI, III, and IV only Question 17: Evaluate the following statements regarding the standard preparation and procedure for conducting an Oral Glucose Tolerance Test (OGTT):I. The subject must consume a carbohydrate-poor diet for at least 3 days prior to testing.II. All drugs known to affect carbohydrate metabolism should be discontinued for at least 2 days before the test.III. The subject should undergo a minimum of 10 hours of overnight fasting.IV. A standard oral load of 75 grams of glucose dissolved in 300 ml of water is administered to be consumed within 5 minutes.Which of the statements are correct?I, II, and III onlyII, III, and IV onlyI, III, and IV onlyI and IV only Question 18: This question consists of two statements: an Assertion and a Reason. Read them carefully and select the correct option.Assertion: Premature and underweight infants are highly susceptible to developing hypoglycemia.Reason: These infants have significantly smaller stores of hepatic glycogen at birth.Both the Assertion and the Reason are correct, and the Reason is the correct explanation of the Assertion.Both the Assertion and the Reason are correct, but the Reason is not the correct explanation of the Assertion.The Assertion is correct, but the Reason is incorrect.The Assertion is incorrect, but the Reason is correct. Question 19: This question consists of two statements: an Assertion and a Reason. Read them carefully and select the correct option.Assertion: Patients with uncontrolled diabetes mellitus frequently develop hypertriglyceridemia characterized by elevated plasma levels of VLDL and chylomicrons.Reason: In diabetic states, the activity of the enzyme lipoprotein lipase is significantly reduced, which impairs the clearance of these lipoprotein fractions.Both the Assertion and the Reason are correct, and the Reason is the correct explanation of the Assertion.Both the Assertion and the Reason are correct, but the Reason is not the correct explanation of the Assertion.The Assertion is correct, but the Reason is incorrect.The Assertion is incorrect, but the Reason is correct. Question 20: A diabetic patient's laboratory report indicates a glycated hemoglobin (HbA1c) concentration of 9.0%. Using the American Diabetes Association formula for Estimated Average Glucose (eAG):eAG (mg/dl) = (28.7 × HbA1c) - 46.7Calculate the patient's approximate estimated average glucose (eAG) in mg/dl.183 mg/dl212 mg/dl240 mg/dl258 mg/dl
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