Question 1

The membrane-lined bridges spanning the cell walls between plant cells are known as

Accepted Answer

A)   gap junctions.
B)   tight junctions.
C)   plasmodia.
D)   plasmodesmata.
E)   G protein receptors.

Question 2

What do G protein-linked receptors and protein kinases have in common?

Accepted Answer

A)   Ligand binding
B)   Conformational change once the ligand is bound
C)   Amplification of the signal
D)   All of the above
E)   None of the above

Question 3

For a G protein to play its part in moving events forward in a signal pathway,

Accepted Answer

A)   GDP must be released, and a GTP must occupy the nucleotide-binding site.
B)   GTP must be released, and a GDP must occupy the nucleotide-binding site.
C)   cGMP must occupy the otherwise empty nucleotide-binding site.
D)   cGMP must leave the otherwise occupied nucleotide-binding site.
E)   None of the above

Question 4

Plasmodesmata

Accepted Answer

A)   are, like gap junctions, made of connexin.
B)   present in animal cells.
C)   can allow the passage of particles as large as viruses from cell to cell.
D)   have a pore diameter of 6 nm.
E)   are made from an endomembrane.

Question 5

Which of the following is true about acetylcholine?

Accepted Answer

A)   It binds to a sodium channel receptor.
B)   It acts as a neurotransmitter.
C)   The binding of two molecules of acetylcholine to a receptor are required to open the channel.
D)   It moves against the concentration gradient.
E)   All of the above

Question 6

Which of the following represents the correct ordering of the molecules that are activated by a single molecule of epinephrine, from highest number of molecules to lowest number of molecules?

Accepted Answer

A)   cAMP, protein kinase A, phosphorylase kinase, glycogen phosphorylase
B)   Glycogen phosphorylase, phosphorylase kinase, protein kinase A, cAMP
C)   cAMP, phosphorylase kinase, glycogen phosphorylase, protein kinase A
D)   Glycogen phosphorylase, cAMP, protein kinase A, phosphorylase kinase
E)   Phosphorylase kinase, glycogen phosphorylase, cAMP, protein kinase A

Question 7

Gap junctions and plasmodesmata differ in that

Accepted Answer

A)   gap junctions are connected by protein tubules called connexons, whereas plasmodesmata are connected by extensions of the plant's plasma membrane.
B)   gap junctions allow much larger molecules to pass through them.
C)   gap junctions have no real physical connection but are rather the space between adjacent cell membranes.
D)   one is of animal origin and the other is of plant origin.
E)   gap junctions are connected by desmotubules and plasmodesmata are connected by connexons.

Question 8

Signals reach target cells in multicellular organisms via _______ and _______.

Accepted Answer

A)   circulation; diffusion
B)   conduction; diffusion
C)   circulation; perspiration
D)   chaperon trafficking; transmembrane transport
E)   cytoskeletal trafficking; perfusion

Question 9

Which of the following represents the correct order of signal transduction?

Accepted Answer

A)   Binding of signal, release of secondary messenger, alteration of receptor conformation, alteration of cellular function
B)   Binding of signal, release of secondary messenger, alteration of receptor conformation, transcription of gene
C)   Binding of signal, activation of target protein by responder, alteration of receptor conformation, release of secondary messenger; transcription of gene
D)   Binding of signal, alteration of receptor conformation, alteration of cellular function, release of second messenger
E)   Binding of signal, alteration of receptor conformation, activation of target protein by responder, alteration of cellular function

Question 10

Which of the following statements about calcium is true?

Accepted Answer

A)   Calcium ions are more concentrated inside than outside the cell.
B)   Active transport maintains the concentration difference of calcium ions.
C)   A cell can increase intracellular concentrations of calcium by making more calcium.
D)   IP3 is the only signal that causes calcium channels to open.
E)   It inhibits cell division in fertilized eggs.

Question 11

A benefit of the many steps involved in protein kinase cascades is that they allow for

Accepted Answer

A)   some specificity of the response.
B)   amplification of the signal.
C)   information to be communicated to the nucleus.
D)   variation in the response.
E)   All of the above

Question 12

Draw what would happen when a hormone binds to a receptor, as shown in the diagram below.

Accepted Answer

The answer of Draw what would happen when a hormone...

Question 13

A protein found in abnormal form in many human bladder cancer cells, _______, is a G protein.

Accepted Answer

The answer of A protein found in abnormal form in...

Question 14

A molecule that binds to the particular three-dimensional structure of another molecule's receptor site is known as a(n)

Accepted Answer

A)   responder.
B)   receptor.
C)   ligand.
D)   ion channel.
E)   filament.

Question 15

E. coli cells respond to osmotic changes by

Accepted Answer

A)   changing the permeability of the membrane.
B)   changing the DNA that is transcribed.
C)   phosphorylating OmpR.
D)   binding the ligand to EnvZ.
E)   increasing metabolism.

Question 16

In _______ transduction, the more common mode of transduction, another molecule, known as a(n) _______ mediates further interaction between the receptor and the response of the cell.

Accepted Answer

indirect; ...

Question 17

Which of the following statements about cell signaling in voles is false?

Accepted Answer

A)   A signal transduction pathway can bring about changes in behavior.
B)   Oxytocin and vasopressin are signals that induce bonding and caring behaviors in voles.
C)   Oxytocin acts as a signal for premating behaviors.
D)   The interaction of the receptor and the signal causes the receptor to change shape.
E)   Although oxytocin and vasopressin are widely circulated in the bloodstream, they only bind to a few cell types.

Question 18

Which of the following statements about the insulin receptor is false?

Accepted Answer

A)   It autophosphorylates.
B)   It requires binding by two insulin molecules to be activated.
C)   It catalyzes the phosphorylation of insulin response substrates.
D)   It is located entirely within the cytoplasm.
E)   None of the above

Question 19

A molecule that binds to a receptor site in another molecule is known as a(n) _______.

Accepted Answer

The answer of A molecule that binds to a receptor...

Question 20

Viagra, used to treat erectile dysfunction, acts by means of the release of the second messenger

Accepted Answer

A)   cyclic AMP.
B)   calcium ion.
C)   nitric oxide.
D)   calmodulin.
E)   acetylcholine.

Exam 7: Cell Signaling and Communication

A benefit of the many steps involved in protein kinase cascades is that they allow for

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Gap junctions and plasmodesmata differ in that

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Signals reach target cells in multicellular organisms via _______ and _______.

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Plasmodesmata

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The membrane-lined bridges spanning the cell walls between plant cells are known as

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What do G protein-linked receptors and protein kinases have in common?

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A molecule that binds to the particular three-dimensional structure of another molecule's receptor site is known as a(n)

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Which of the following represents the correct order of signal transduction?

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Which of the following statements about calcium is true?

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A molecule that binds to a receptor site in another molecule is known as a(n) _______.

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Which of the following is true about acetylcholine?

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Draw what would happen when a hormone binds to a receptor, as shown in the diagram below.

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A protein found in abnormal form in many human bladder cancer cells, _______, is a G protein.

Correct AnswerverifiedShow Answer

Which of the following statements about cell signaling in voles is false?

Correct AnswerverifiedShow Answer

Which of the following statements about the insulin receptor is false?

Correct AnswerverifiedShow Answer

Which of the following represents the correct ordering of the molecules that are activated by a single molecule of epinephrine, from highest number of molecules to lowest number of molecules?

Correct AnswerverifiedShow Answer

Viagra, used to treat erectile dysfunction, acts by means of the release of the second messenger

Correct AnswerverifiedShow Answer

For a G protein to play its part in moving events forward in a signal pathway,

Correct AnswerverifiedShow Answer

E. coli cells respond to osmotic changes by

Correct AnswerverifiedShow Answer

In _______ transduction, the more common mode of transduction, another molecule, known as a(n) _______ mediates further interaction between the receptor and the response of the cell.

Correct Answerverifiedindirect; ...View AnswerShow Answer

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Signals reach target cells in multicellular organisms via _ and _.

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In _ transduction, the more common mode of transduction, another molecule, known as a(n) _ mediates further interaction between the receptor and the response of the cell.

Correct Answer
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indirect; ...
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