Cancer is believed to often arise from stem cells, rather than fully differentiated cells. Which of the following are consistent with this view?

#Question id: 1156

#Unit 4. Cell Communication and Cell Signaling

Which of the following mechanisms cannot terminate an intracellular signaling pathway once the concentration of an external signal decreases?

#Question id: 1157

#Unit 4. Cell Communication and Cell Signaling

When the regulatory domain of PKA is bound to cAMP:

#Question id: 1158

#Unit 4. Cell Communication and Cell Signaling

Muscarinic acetylcholine receptors are GPCRs that slow the rate of heart muscle contraction upon ligand binding/activation. Activation of this receptor leads to opening of potassium channels triggered by decreases in cAMP levels. The muscarinic acetylcholine receptor likely couples to:

#Question id: 1159

#Unit 4. Cell Communication and Cell Signaling

Cholera toxin can make you sick through overactivation of a Gs pathway even if your body stops making the ligand associated with activation of the pathway. Knowing this, which of the following CANNOT be true about cholera toxin?

#Question id: 1160

#Unit 4. Cell Communication and Cell Signaling

Signal amplification is an important part of GPCR-mediated signaling. Which of the following steps do NOT directly amplify the signal?

#Question id: 1161

#Unit 4. Cell Communication and Cell Signaling

A mutation renders a Gαq subunit constitutively active (also known as dominant active). Which of the following effects might you observe in a cell with this mutation?