Questions and answers for exam Preparation

MCQs

Total Questions : 121 | Page 11 of 13 pages

Question 101. . What is the name of the protein signaling molecule that alters glucose uptake, and where would its receptors be located?

Insulin; many different cell types that use glucose for fuel
Insulin; beta cells of the pancreas
PDGF; the blood
NGF; the nerves involved in simple reflexes

Discuss Question

Answer: Option A. -> Insulin; many different cell types that use glucose for fuel

Question 102. . In the signal transduction mechanism known as protein phosphorylation

the signaling molecule binds to a surface receptor
receptor kinases play a key role in triggering the signal cascade
phosphorylated proteins act with enzymes to trigger the signal cascade
All of the above

Discuss Question

Answer: Option D. -> All of the above

Question 103. . Cell signaling can be classified into

three distinct types based on the distance over which the signaling molecules act
two distinct types based on the distance over which the signaling molecules act
three distinct types based on the signaling molecules
none of the above

Discuss Question

Answer: Option A. -> three distinct types based on the distance over which the signaling molecules act

Question 104. . Which of the following statement is correct?

Cell communicate with one another in multicellular organisms using extracellular signaling molecules or hormones
Cell communicate with one another in unicellular organisms using extracellular signaling antigen and antibody
Cell communicate with one another in multicellular organisms using intracellular signaling molecules only
Cell communicate with one another in unicellular organisms using intracellular signaling antigen and antibody

Discuss Question

Answer: Option A. -> Cell communicate with one another in multicellular organisms using extracellular signaling molecules or hormones

Question 105. . In vasodilation, proper nerve signals sent to blood vessels cause

the release of nitric oxide from endothelial cells
relaxation of smooth muscle cells
reduced blood pressure
All of the above

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Answer: Option D. -> All of the above

Question 106. . A cell is known to respond to a particular signaling molecule. Which of the following must be true of this cell?

It is in the heart muscle
It is also the site of production for the signaling molecule
It contains the receptor for the signaling molecule
It is incapable of signal transduction

Discuss Question

Answer: Option C. -> It contains the receptor for the signaling molecule

Question 107. . The enzyme that catalyzes the splitting of PIP2 into two molecules of inositol triphosphate (IP3) and diacylglycerol in cell signaling, is

phosphokinase C
phospholipase C
phosphodiesterase C
lipokinase

Discuss Question

Answer: Option B. -> phospholipase C

Question 108. . The binding of ligands to many G-proteins linked receptors leads to shortlived

increase in the concentration of certain intracellular signaling molecules called second messenger
decrease in the concentration of certain intracellular signaling molecules called second messenger
increase in the concentration of certain extracellular signaling molecules called first messenger
decrease in the concentration of certain extracellular signaling molecules called first messenger

Discuss Question

Answer: Option A. -> increase in the concentration of certain intracellular signaling molecules called second messenger

Question 109. . Which of the following processes involve the combining of a message from one signaling molecule with that of another to either enhance or inhibit a cellular effect?