AP BIOLOGY UNIT 4 QUESTIONS WITH 100% CORRECT
ANSWERS GRADED A+ 2025
What is endocrine signaling? Hormones travel long distances through the bloodstream to
reach target cells
What is juxtacrine signaling? Direct communication where signaling occurs through pysical cell
contance
What is quorum sensing? A process where cells detect the local concentration of
signaliing molcules and initate a coordinated response
once a threshold is reached
What is a ligand? A molecule that binds to a receptor to iniate signaling; signal
What is a receptor? A protein that receives and binds to a ligand
What is a ligand-gated ion A membrane receptor that opens in response to
channel? ligand binding, allowing ions to flow through
What is a GPCR (G-protein- A receptro that activates a G-protein upon ligand binding,
coupled receptor)? initating a signal cascade and amplified cellular
response
What is a second messenger? A small, water-soluble molecule that transmits signals
from receptors to target molecules
What is a signal transduction A series of molecular events that convert a signal into a specific
pwathway? cellular response
What is a phosphorylation A series of protein activation via phosphorylation that
cascade? amplifies the original signal
What is signal amplification? The process where one signal molecule causes a large
number of downstream responses
What happens during signal A signal molecules binds to its receptor
reception?
What happens during The external signal is relayed and amplifed through molecular
transduction? interactions
What happens during the A cell responds through gene expresion, enzyme activation, or
response phase of changes in function
signaling?
What is negative feedback? A process where they system responds to a change by
reducing or reversing that change, restoring stability
ANSWERS GRADED A+ 2025
What is endocrine signaling? Hormones travel long distances through the bloodstream to
reach target cells
What is juxtacrine signaling? Direct communication where signaling occurs through pysical cell
contance
What is quorum sensing? A process where cells detect the local concentration of
signaliing molcules and initate a coordinated response
once a threshold is reached
What is a ligand? A molecule that binds to a receptor to iniate signaling; signal
What is a receptor? A protein that receives and binds to a ligand
What is a ligand-gated ion A membrane receptor that opens in response to
channel? ligand binding, allowing ions to flow through
What is a GPCR (G-protein- A receptro that activates a G-protein upon ligand binding,
coupled receptor)? initating a signal cascade and amplified cellular
response
What is a second messenger? A small, water-soluble molecule that transmits signals
from receptors to target molecules
What is a signal transduction A series of molecular events that convert a signal into a specific
pwathway? cellular response
What is a phosphorylation A series of protein activation via phosphorylation that
cascade? amplifies the original signal
What is signal amplification? The process where one signal molecule causes a large
number of downstream responses
What happens during signal A signal molecules binds to its receptor
reception?
What happens during The external signal is relayed and amplifed through molecular
transduction? interactions
What happens during the A cell responds through gene expresion, enzyme activation, or
response phase of changes in function
signaling?
What is negative feedback? A process where they system responds to a change by
reducing or reversing that change, restoring stability
