01
True or false
1 point
A ligand is present outside a cell, but the cell lacks the receptor that recognizes it. Can the ligand trigger its usual receptor-mediated response in that cell?
Free Practice Quiz Question List
4 Cell Signaling Online Quiz Questions
Use this free practice quiz with 20 questions to review 4 Cell Signaling, test your knowledge, and prepare for your next test or exam.
20 questions
02
Choose one
1 point
A neurotransmitter binds a ligand-gated ion channel on a target cell. What is the most direct expected effect?
- A
It directly changes gene expression by carrying the ligand into the nucleus.
- B
It changes ion flow across the membrane, often rapidly altering the cell’s electrical state.
- C
It converts ATP into cAMP.
- D
It breaks down extracellular ligands.
03
Fill in the blank
1 point
After a ligand binds its receptor, intracellular steps relay and process the signal before the cell changes its activity. This middle stage is called .
04
Written response
1 point
In the example GPCR pathway, what enzyme converts ATP into cAMP after stimulation by a G protein?
05
Choose one
1 point
A steroid hormone crosses the plasma membrane and its ligand-bound receptor directly influences gene expression. Which receptor location best fits this mechanism?
- A
A ligand-gated ion channel, because steroid hormones cannot cross the membrane.
- B
An intracellular receptor, whose ligand-bound complex can regulate gene expression.
- C
A GPCR, because all hormones signal through G proteins.
- D
A receptor tyrosine kinase, because all growth-related signals act inside the nucleus.
06
Choose all
1 point
Select all accurate statements about second messengers.
- A
They can carry information from an activated receptor to intracellular targets.
- B
They are always the extracellular ligand itself.
- C
Their production and removal can help control where and how long a signal acts.
- D
They are receptors that bind ligands outside the cell.
07
True or false
1 point
Every GPCR pathway raises cAMP because activated G proteins always stimulate adenylyl cyclase.
- A
True
- B
False
08
Fill in the blank
1 point
In the phospholipase C pathway, IP3 can trigger the release of from intracellular stores.
09
Choose all
1 point
Select all statements that correctly describe the phospholipase C pathway.
- A
Phospholipase C splits PIP2 into IP3 and DAG.
- B
IP3 is the enzyme that splits PIP2.
- C
IP3 can trigger calcium release from intracellular stores.
- D
DAG and calcium can work together to activate protein kinase C.
10
Written response
1 point
Which second messenger is broken down by phosphodiesterases to help shut off a signaling pathway?
11
Choose one
1 point
A growth factor activates a receptor that phosphorylates itself and other proteins, followed by a relay that may involve Ras and a MAPK cascade. Which receptor mechanism best explains this?
- A
A ligand-gated ion channel directly activates PKA to regulate growth.
- B
An intracellular steroid receptor opens a channel to start the Ras–MAPK cascade.
- C
A receptor tyrosine kinase phosphorylates proteins and may initiate a Ras–MAPK cascade.
- D
A GPCR must always inhibit adenylyl cyclase to activate Ras.
12
Choose one
1 point
A cell receives two signals at once, and its response depends on how their pathways interact. Which pathway property best explains this integration?
- A
The cell must respond to each signal independently, with no interaction between pathways.
- B
All signals converge on one receptor before entering the cell.
- C
Pathways can branch, converge, and interact, allowing the cell to combine multiple signals.
- D
Signal integration means the ligand changes into a different ligand.
13
Open ended
1 point
Explain how an activated receptor can amplify a signal and why amplification does not require the cellular response to continue indefinitely. Include at least one pathway shutoff mechanism.
14
Choose one
1 point
Which cell is able to respond to a particular signaling ligand?
- A
Any cell that is exposed to the ligand
- B
A cell with the appropriate receptor for the ligand
- C
Only a cell that can produce the ligand itself
- D
Only a cell with an intracellular receptor
15
True or false
1 point
True or false: A steroid hormone that crosses the plasma membrane can bind an intracellular receptor, and the resulting complex can directly regulate gene expression.
- A
True
- B
False
16
Written response
1 point
What is the term for a small intracellular molecule or ion that carries a signal from an activated receptor to other targets?
17
Choose one
1 point
A ligand binds a receptor and rapidly changes ion flow across the plasma membrane, altering the cell's electrical state. Which receptor type best fits this description?
- A
Intracellular receptor
- B
Enzyme-linked receptor
- C
Ligand-gated ion channel
- D
G protein-coupled receptor
18
Written response
1 point
In a GPCR pathway, what enzyme converts ATP into cyclic AMP?
19
Choose one
1 point
In a GPCR pathway, cAMP activates protein kinase A (PKA). What does PKA then do in the pathway described?
- A
PKA converts ATP into cAMP
- B
PKA phosphorylates target proteins
- C
PKA splits PIP₂ into IP₃ and DAG
- D
PKA binds the extracellular ligand
20
Choose one
1 point
A growth factor binds its receptor, and the cell begins a signaling relay that may regulate growth and division. Which sequence best fits this pathway?
- A
Receptor tyrosine kinase activation followed by a Ras and MAPK relay
- B
Ligand-gated ion channel opening followed by cAMP breakdown
- C
Intracellular receptor activation followed by PIP₂ cleavage
- D
G protein inactivation followed by IP₃ production