COMPREHENSIVE BASIC SCIENCE EXAM CBSE REVIEW

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COMPREHENSIVE BASIC SCIENCE EXAM (CBSE) REVIEW

SET I Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -99 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Treats cyanide poisoning by first oxidizing hemoglobin to methemoglobin then (indirectly) binding cyanide forming cyanmethemoglobin diverting it from cytochrome complex IV

Answer:

Sodium Nitroprusside Question 2: Charged ionic attraction between positive lysine residues & negative DNA occurs thru the removal of acetyl groups by histone deacetylase; resulting in DNA histones binding more tightly, restricting transcription

Answer:

• Diphtheria

Question 3: Ability amongst segmented viruses, BOAR, to exchange segments intracellularly when coinfecting a host cell

Answer:

Viral complementation

Question 4: Increased RV afterload that can lead to cor pulmonale

Harder to eject blood during systole causing delayed closure of pulmonary valve- wide/fixed S2 split Increased velocity when pulmonary valve does close from increased diastolic pressure- loud P2

Answer:

Cortisol Question 5: A DNA repair pathway that involves excision of a damaged base by DNA glycosylase Followed by cleavage of the DNA backbone adjacent to the site by an AP endonuclease Nick translation, DNA polymerization, and ligation complete the repair

Answer:

Daptomycin Question 6: Treats cyanide poisoning by bonding directly & forming cyanocobalamin which is excreted by the kidneys

Answer:

Sodium thiosulfate Question 7: Deficiency in sphingomyelinase resulting in accumulation of the lipid sphingomyelin due to mutation in SMPD1 gene Presents w/ Enlarged spleen & liver, Jaundice, intellectual deficit, "Cherry-red" spots in eyes, & Muscle weakness,

Answer:

Histones

Question 8: Chagas Disease

Answer:

Caused by Trypanosoma cruzi parasite passed in the feces of Reduviidae/kissing bug Penetrates broken skin or intact mucous membranes forming a pseudocyst releasing inflammatory infiltrates into myocytes; stains with Giemsa & Wright Romana sign occurs when portal of entry is the conjunctiva or eyelid

May resulting in:

Enlarged heart- CHF, sudden cardiac arrest Enlarged esophagus- difficulty swallowing Enlarged colon- abdominal pain or constipation Treat with benznidazole or nifurtimox

Question 9: HLA-B27

Answer:

PAIR:

Psoriasis Ankylosing spondylitis- chronic synovitis destroying cartilage typically in young men Inflammatory bowel dz- Crohn's & UC Reactive Arthritis-

Question 10: Naproxen

Answer:

ADR of GI & renal (in elderly) Question 11: Inherited failure of tumor supressor menin resulting in parathyroid, pancreas, & pituitary tumors

Answer:

Zollinger-Ellison syndrome

Question 12: Descrepancy between placental genotype & that of the fetus

Answer:

Kartagener's syndrome

Question 13: Long QT syndrome

Answer:

Rare inborn heart condition in which delayed repolarization of the heart following a heartbeat increases the risk of episodes of torsade de pointes and other life threatening arrhythmias. Prolongation of the QT interval is a diagnostic of the condition.KCNQ1 and KCNE1 Question 14: Deletion of 3 DNA base pairs that code for phenylalanine in the CFTR gene at the delta 508 position Results in protein misfolding & subsequent Chloride channel dysfunction Presents as failure to thrive, abdominal distention, steatorrhea, & anemia indicating malnutrition along w/ recurrent URIs & exocrine pancreatic insufficiency

Answer:

Primase

Question 15: Gaucher (Type 1)

Answer:

AR Lysosomal storage disease Accumulation of sphingolipid glucocerebroside Most common Wrinkled tissue paper Question 16: Impaired transport of LCFAs into the mitochondrial matrix, the substrate needed for B-oxidation Resulting in toxic accumulation & hypoketonemia

Answer:

Zellweger syndrome Question 17: Endotoxin lipid A, part of LPS gram negative cell wall, causes inflammation by activation of macrophages & complement cascade (TNFa, IL-1, & IL-6) causing further release of inflammatory mediators nitric oxide & histamine producing hypotension due to septic shock Associated with sickle cell & cystic fibrosis

Answer:

• Meningitidis

Question 18: Binds cyclophilin inhibiting calcineurin that promotes interleukin?2 synthesis, suppressing T cells reducing risk of transplant rejection (not myelosuppressant) ADR: hirsutism, gingival hyperplasia, hyperlipidemia, HTN, nephrotoxicity (dose?limiting), & seizures (overdose)

Answer:

Anterior Pituitary hormones

Question 19: alkylating agent used to treat cancers

ADR:

Reduce toxicity with Mesna

Answer:

Cyclosporine Question 20: Unlike other nitrates does NOT undergo 1st pass metabolism by the liver w/ nearly 100% bioavailability, providing means of oral treatment for preventation of angina by CAD thru dephosphorylation of myosin light chains

Answer:

Itraconazole (Sporanox)