Biomedical Sciences Flashcards
7 cards from real STP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Biomedical Sciences flashcards as text
In a CRISPR-Cas9 experiment, what determines the sequence specificity of the cut?
Answer: The guide RNA sequence complementary to the target DNA
The ~20-nucleotide guide RNA spacer sequence base-pairs with the target DNA strand, directing Cas9 to the correct genomic locus adjacent to a PAM.
Which immunoglobulin class is the most abundant in human serum and is capable of crossing the placenta?
Answer: IgG
IgG is the predominant serum immunoglobulin and is actively transported across the placenta via FcRn receptors, conferring passive immunity to the fetus.
A researcher measures increased lactate production in cancer cells even in the presence of oxygen. This phenomenon is known as:
Answer: The Warburg effect
The Warburg effect describes aerobic glycolysis in cancer cells, where glucose is preferentially converted to lactate despite sufficient oxygen.
Which assay directly measures the affinity (Kd) of a protein-ligand interaction in real time without labeling?
Answer: Surface plasmon resonance (SPR)
SPR measures changes in refractive index as molecules bind to an immobilized ligand on a sensor chip, providing real-time, label-free kinetic data.
What is the function of signal recognition particle (SRP) in protein targeting?
Answer: It recognizes signal sequences and arrests translation until the ribosome docks with the ER
SRP binds the emerging signal peptide and pauses translation, then delivers the ribosome-mRNA-nascent chain complex to the ER translocon.
Which mutation type causes sickle cell disease by substituting a single amino acid in hemoglobin?
Answer: Missense mutation
A GAG→GTG point mutation in the HBB gene causes a glutamate-to-valine substitution (E6V) — a missense mutation — producing HbS.
In a clinical trial, which study design provides the highest level of evidence for evaluating a new therapeutic intervention?
Answer: Randomized controlled trial (RCT)
RCTs randomly assign participants to treatment or control groups, minimizing confounding and providing the strongest causal evidence for intervention efficacy.