Scientific Knowledge Flashcards
7 cards from real Physician Assistant practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Scientific Knowledge flashcards as text
Which genetic mutation pattern is associated with familial adenomatous polyposis (FAP)?
Answer: Autosomal dominant loss-of-function mutation in APC
FAP results from autosomal dominant loss-of-function mutations in the APC tumor suppressor gene, causing hundreds to thousands of colorectal polyps.
Which mechanism allows viruses to evade the immune system by downregulating MHC class I expression?
Answer: Preventing cytotoxic T cells from recognizing infected cells
Downregulation of MHC class I prevents CD8+ cytotoxic T cells from recognizing viral peptides presented on infected cells, allowing viral persistence.
In the coagulation cascade, which factor is shared between the intrinsic and extrinsic pathways at the common pathway junction?
Answer: Factor X
Factor X is activated by both the intrinsic pathway (via IXa/VIIIa) and the extrinsic pathway (via VIIa/TF) and initiates the common coagulation pathway.
Which phase of pharmacokinetics involves the chemical transformation of a drug, typically in the liver?
Answer: Metabolism (biotransformation)
Metabolism (biotransformation) refers to enzymatic modification of drugs, primarily by cytochrome P450 enzymes in the liver, to facilitate elimination.
The renin-angiotensin-aldosterone system (RAAS) is activated primarily by which stimulus?
Answer: Decreased renal perfusion pressure
Decreased renal perfusion pressure triggers juxtaglomerular cells to release renin, initiating the RAAS cascade to restore blood pressure and volume.
In genetics, incomplete dominance results in which pattern of inheritance?
Answer: Intermediate phenotype in heterozygotes
Incomplete dominance produces an intermediate phenotype in heterozygotes, as neither allele fully dominates the other (e.g., red × white = pink flowers).
Which organelle is responsible for protein sorting, post-translational modifications, and packaging for secretion?
Answer: Golgi apparatus
The Golgi apparatus receives proteins from the RER, performs glycosylation and other modifications, and sorts them into vesicles for secretion or intracellular delivery.