Name: 
 

Chapter 11 Online Questions



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Which of the following is not true of cell communication systems?
a.
Cell signaling was an early event in the evolution of life.
b.
Communicating cells may be far apart or close together.
c.
Most signal receptors are bound to the outer membrane of the nuclear envelope.
d.
Protein phosphorylation is a major mechanism of signal transduction.
e.
In response to a signal, the cell may alter activities by changes in cytosol activity or in transcription of RNA.
 

 2. 

Which of the following is not part of the phosphorylation cascade model?
a.
A signal molecule binds to a membrane receptor protein.
b.
Protein kinase is activated.
c.
GTP donates a phosphate group to an inactive protein kinase.
d.
A specific protein is activated via phosphorylation.
e.
A cellular response is initiated.
 

 3. 

The process of transduction usually begins
a.
when the chemical signal is released from the alpha cell.
b.
when the signal molecule changes the receptor protein in some way.
c.
after the target cell divides.
d.
after the third stage of cell signaling is completed.
e.
when the hormone is released from the gland into the blood.
 

 4. 

Which of the following are chemical messengers that pass through the plasma membrane of cells and have receptor molecules in the cytoplasm?
a.
insulin
b.
nitric oxide
c.
testosterone
d.
B and C only
e.
A, B, and C
 

 5. 

Paracrine signaling
a.
involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid.
b.
requires nerve cells to release a neurotransmitter into the synapse.
c.
occurs only in paracrine yeast cells.
d.
has been found in plants but not animals.
e.
involves mating factors attaching to target cells and causing production of new paracrine cells.
 

 6. 

Up to 60% of all medicines used today exert their effects by influencing what structures in the cell membrane?
a.
tyrosine-kinases receptors
b.
ligand-gated ion channel receptors
c.
growth factors
d.
G proteins
e.
cholesterol
 

 7. 

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?
a.
lower cytoplasmic levels of cAMP
b.
an increase in receptor tyrosine kinase activity
c.
a decrease in transcriptional activity of certain genes
d.
an increase in cytosolic calcium concentration
e.
a decrease in G-protein activity
 

 8. 

Which of the following is not considered a second messenger?
a.
cAMP
b.
GTP
c.
calcium ions
d.
diacylglycerol (DAG)
e.
inositol trisphosphate (chpt11_files/i0090000.jpg)
 

 9. 

Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to
a.
the active site of an enzyme in the cytoplasm that binds to a specific substrate.
b.
RNA specifying the amino acids in a polypeptide.
c.
a particular metabolic pathway operating within a specific organelle.
d.
an enzyme with an optimum pH and temperature for activity.
e.
genes making up a chromosome.
 

 10. 

The response of a particular cell to a signal depends on
a.
its particular collection of signal receptor proteins.
b.
its relay proteins.
c.
the proteins needed to carry out the response.
d.
A and B only
e.
A, B, and C
 

 11. 

Which of the following is true of synaptic signaling and hormonal signaling?
a.
Hormonal signaling occurs in animals only.
b.
Hormonal signaling is important between cells that are at greater distances apart than in synaptic signaling.
c.
Both act on target cells by a G-protein-signaling pathway.
d.
Only A and B are true.
e.
A, B, and C are true.
 



 
Check Your Work     Reset Help