D236 Pathophysiology - Set 1 - Part 2

Correct Answer: Penetrance percentage

Penetrance represents the percentage of individuals with a disease gene who manifest symptoms, explaining incomplete disease expression patterns.
Option a is incorrect because variable expressivity refers to different severity levels among affected individuals, not presence versus absence.
Option c is incorrect because genetic dominance describes how alleles interact but not the percentage showing disease symptoms.
Option d is incorrect because allelic frequency measures how common a gene variant is in populations, not symptom expression.

Correct Answer: Transfer RNA molecule

Transfer RNA molecules bring specific amino acids to ribosomes and align them according to messenger RNA codon sequences.
Option b is incorrect because ribosomal RNA forms the ribosome structure but doesn't transport amino acids for protein assembly.
Option c is incorrect because micro RNA regulates gene expression post-transcriptionally but doesn't carry amino acids to ribosomes.
Option d is incorrect because small nuclear RNA participates in splicing but doesn't transport amino acids during translation.

Correct Answer: Renal compensation

Renal compensation takes days but provides complete correction by excreting acid and retaining bicarbonate to restore balance.
Option a is incorrect because respiratory compensation acts quickly but cannot fully correct metabolic problems without kidney involvement.
Option c is incorrect because protein buffering provides immediate but limited capacity that cannot sustain long-term pH correction.
Option d is incorrect because phosphate buffering works intracellularly with limited capacity compared to renal compensation mechanisms.

Correct Answer: Enhancer region

Enhancer regions bind transcription factors to increase gene expression rates, functioning even from distant DNA locations effectively.
Option a is incorrect because promoters are adjacent to genes where transcription begins, not distant regulatory regions described.
Option c is incorrect because silencers decrease rather than increase transcription rates when activated by regulatory factors.
Option d is incorrect because terminators signal where transcription ends, not regions that increase transcription rates from distance.

Correct Answer: Karyotype analysis

Karyotype analysis displays all chromosomes to identify numerical abnormalities like trisomy or monosomy conditions affecting entire chromosomes.
Option a is incorrect because gene sequencing examines DNA sequences for mutations but doesn't visualize whole chromosome numbers.
Option c is incorrect because protein electrophoresis separates proteins by charge and size, not for examining chromosome numbers.
Option d is incorrect because metabolic screening tests for biochemical disorders but doesn't directly examine chromosome structure or number.

Correct Answer: Dendritic cells

Dendritic cells capture antigens in peripheral tissues then migrate to lymph nodes to activate T lymphocyte responses.
Option a is incorrect because neutrophils are early responders that phagocytose bacteria but don't primarily present antigens to lymphocytes.
Option c is incorrect because basophils release inflammatory mediators in allergic responses but aren't primary antigen presenting cells.
Option d is incorrect because eosinophils combat parasites and participate in allergic responses rather than antigen presentation.

Correct Answer: Chondrocyte cells

Chondrocytes become overactive under mechanical stress, producing enzymes that degrade cartilage matrix in osteoarthritis development progressively.
Option a is incorrect because synovial cells produce joint fluid but aren't the primary cells breaking down cartilage matrix.
Option c is incorrect because osteocytes maintain bone tissue rather than cartilage, though bone changes occur secondarily.
Option d is incorrect because fibroblasts produce connective tissue but aren't the main cells responsible for cartilage degradation.

Correct Answer: Mother carried the gene

Males inherit X-linked recessive conditions from carrier mothers since they receive their single X chromosome maternally.
Option a is incorrect because X-linked inheritance requires only the mother to carry it for male offspring expression.
Option c is incorrect because fathers pass Y chromosomes to sons, not the X chromosome carrying color blindness genes.
Option d is incorrect because while possible, most X-linked conditions result from maternal inheritance rather than new mutations.

Correct Answer: Increased blood flow

Vasodilation increases blood flow to inflamed areas, causing the redness and warmth characteristic of acute inflammatory responses.
Option a is incorrect because decreased blood flow would cause pallor and coolness, opposite of inflammation's clinical signs.
Option c is incorrect because nerve stimulation causes pain sensations but not the redness and warmth from vascular changes.
Option d is incorrect because muscle contraction might generate some heat but doesn't cause the vascular-mediated redness observed.

Correct Answer: Gene mapping technique

Gene mapping identifies specific chromosomal locations of genes, crucial for understanding genetic disease inheritance and potential interventions.
Option b is incorrect because protein synthesis tracking studies translation but doesn't locate genes on specific chromosome positions.
Option c is incorrect because cell culture grows cells for study but doesn't identify specific gene locations on chromosomes.
Option d is incorrect because tissue typing matches donor-recipient compatibility rather than mapping gene locations for disease.

Correct Answer: Decreased respiratory rate

The body compensates for respiratory alkalosis by decreasing breathing rate to retain carbon dioxide and lower pH levels.
Option a is incorrect because renal compensation takes hours to days, not providing the immediate response needed for correction.
Option c is incorrect because protein buffering has limited capacity and isn't the primary compensation for respiratory alkalosis.
Option d is incorrect because bicarbonate changes are renal responses that take time, not immediate respiratory compensations described.

Correct Answer: Slight movement capability

Amphiarthrosis joints like vertebral connections allow slight movement, providing flexibility while maintaining structural stability between bones.
Option a is incorrect because complete immobility describes synarthrosis joints like skull sutures, not amphiarthrosis joint characteristics.
Option c is incorrect because free movement characterizes diarthrosis or synovial joints, not the limited amphiarthrosis mobility.
Option d is incorrect because rotational movement is one type possible in synovial joints, not amphiarthrosis joint limitation.

Correct Answer: Avoid cerebral edema

Rapid glucose correction with insulin can cause osmotic shifts leading to cerebral edema, requiring careful monitoring during treatment.
Option a is incorrect because while hypoglycemia is concerning, the immediate danger is osmotic shifts causing brain swelling.
Option c is incorrect because insulin doesn't directly affect infection risk during diabetic ketoacidosis treatment protocols used.
Option d is incorrect because blood pressure management is important but not the primary brain complication from insulin administration.

Correct Answer: Chemokine peptides

Chemokines are small peptides that create chemical gradients, specifically inducing directed white blood cell migration to inflammation sites.
Option a is incorrect because histamine increases vascular permeability but doesn't specifically direct white blood cell chemotaxis described.
Option c is incorrect because complement proteins enhance immune responses through various mechanisms but aren't primarily chemotactic signals.
Option d is incorrect because antibodies mark pathogens for destruction but don't primarily function as chemotactic signals.

Correct Answer: Different symptom severity

Variable expressivity means individuals with the same genetic mutation show different disease severity levels or symptom combinations.
Option a is incorrect because variable expressivity refers to phenotype differences, not changes in how genes are inherited.
Option c is incorrect because age of onset is a separate concept from variable expressivity of symptom severity.
Option d is incorrect because treatment response relates to pharmacogenetics rather than the variable expressivity concept described.

Correct Answer: Autosomal dominant pattern

Autosomal dominant conditions appear in every generation affecting both sexes equally, requiring only one mutated gene copy.
Option b is incorrect because autosomal recessive conditions often skip generations when carriers don't show symptoms between affected individuals.
Option c is incorrect because X-linked recessive conditions predominantly affect males and often skip generations through carrier females.
Option d is incorrect because mitochondrial inheritance shows maternal transmission patterns, not equal transmission from both parents.

Correct Answer: Oxygen and nutrients

Capillary endothelial cells facilitate oxygen and nutrient exchange between blood and tissues, essential for wound healing processes.
Option b is incorrect because while antibodies are delivered, endothelial cells primarily facilitate metabolic exchange, not just immunity.
Option c is incorrect because clotting factors are important initially but endothelial cells maintain ongoing metabolic tissue support.
Option d is incorrect because inflammatory cells migrate through vessels but endothelial cells primarily facilitate metabolic exchange described.

Correct Answer: Androgen level elevation

Elevated androgens in polycystic ovarian syndrome cause hirsutism, obesity, menstrual irregularities, and metabolic dysfunction in affected women.
Option a is incorrect because thyroid excess causes different symptoms like heat intolerance and weight loss, not PCOS pattern.
Option c is incorrect because PCOS involves complex hormonal imbalances beyond simple estrogen deficiency, particularly androgen excess described.
Option d is incorrect because progesterone irregularities occur but elevated androgens are the primary driver of PCOS symptoms.

Correct Answer: Protein buffer system

Protein buffers respond immediately to pH changes but have limited capacity compared to respiratory and renal mechanisms.
Option a is incorrect because the carbonic acid system works with respiratory compensation, not as the fastest initial response.
Option c is incorrect because phosphate buffers work primarily intracellularly and aren't the fastest responding system described here.
Option d is incorrect because ammonia buffering occurs in kidneys over time, not as an immediate response system.

Correct Answer: RNA splicing process

RNA splicing removes introns and joins exons to create mature messenger RNA ready for translation into proteins.
Option b is incorrect because capping protects RNA and aids translation initiation but doesn't remove introns as described.
Option c is incorrect because poly-A tailing stabilizes messenger RNA but doesn't involve intron removal from precursors.
Option d is incorrect because methylation modifies RNA function but isn't the intron removal process required before translation.