Question 1

What explains the increased concentration of Ca²⁺ in the ER?

Accepted Answer

A)  Calcium ions are actively imported from the cytoplasm into the ER.
B)  Calcium concentration is kept low in the cytoplasm because of its high usage level.
C)  Calcium cannot enter the plasma membrane through ion channels.
D)  Calcium levels in the blood or other body fluids are extremely low.
E)  The Ca ions are recycled from other molecules in the ER.F) A) and E)
G) A) and C)

Question 2

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

Accepted Answer

A)  Most of the steps were already in place because they are steps in other pathways.
B)  Multiple steps in a pathway require the least amount of ATP.
C)  Multiple steps provide for greater possible amplification of a signal.
D)  Each individual step can remove excess phosphate groups from the cytoplasm.
E)  Each step can be activated by several G proteins simultaneously.F) A) and B)
G) All of the above

Question 3

Sutherland's research showed that cell-to-cell communication can be divided into three distinct parts that follow a particular sequence.In order from first to last,these are

Accepted Answer

A)  transduction, response, reception.
B)  reception, transduction, response.
C)  transcription, translation, response.
D)  transduction, transcription, translation.
E)  first messenger, second messenger, product.F) C) and D)
G) A) and B)

Question 4

A molecule that specifically binds to another molecule (often a larger one) is known as a(n)

Accepted Answer

A)  ligand.
B)  receptor.
C)  transcription factor.
D)  activator.
E)  scaffolding protein.F) A) and B)
G) A) and C)

Question 5

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

Accepted Answer

A)  Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast.
B)  Bacteria and yeast cells may undertake quorum sensing.
C)  Signal transduction molecules identified in distantly related organisms are similar.
D)  Most signals in all types of cells are received by cell surface receptors.
E)  Signals in bacteria are hydrophobic and do not require a cell surface receptor.F) A) and B)
G) A) and C)

Exam 11: Cell Communication

A molecule that specifically binds to another molecule (often a larger one) is known as a(n)

Correct Answer
verified

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

Correct Answer
verified

Sutherland's research showed that cell-to-cell communication can be divided into three distinct parts that follow a particular sequence.In order from first to last,these are

Correct Answer
verified

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

Correct Answer
verified

What explains the increased concentration of Ca²⁺ in the ER?

Correct Answer
verified

Exam 11: Cell Communication

A molecule that specifically binds to another molecule (often a larger one) is known as a(n)

Correct AnswerverifiedShow Answer

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

Correct AnswerverifiedShow Answer

Sutherland's research showed that cell-to-cell communication can be divided into three distinct parts that follow a particular sequence.In order from first to last,these are

Correct AnswerverifiedShow Answer

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

Correct AnswerverifiedShow Answer

What explains the increased concentration of Ca²⁺ in the ER?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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