In an pond ecosystem the _____ is always greater than the _____ .

(a) number of primary producers . . . number of secondary consumers

(b) biomass of secondary consumers . . . biomass of primary consumer

(c) assimilation efficiency of primary consumers . . . assimilation efficiency of secondary consumers

(d) biomass of primary producers . . . biomass of primary consumers

#Question id: 1216

#Unit 4. Cell Communication and Cell Signaling

In yeast signal transduction, a yeast cell releases a mating factor, which:

#Question id: 1217

#Unit 4. Cell Communication and Cell Signaling

Yeast cells of mating type a are genetically engineered to produce only mating factor α instead of the normal mating factor a. The gene for the mating factor receptor was unaltered. How will these engineered cells behave in terms of mating?

#Question id: 1218

#Unit 4. Cell Communication and Cell Signaling

Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. Which of the following conditions is required for the target organ to respond to a particular hormone?

#Question id: 1219

#Unit 4. Cell Communication and Cell Signaling

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would you expect to find the carboxyl end of the protein?

#Question id: 1220

#Unit 4. Cell Communication and Cell Signaling

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would a coupled G protein most likely interact with this receptor?

#Question id: 1221

#Unit 4. Cell Communication and Cell Signaling

If an animal cell suddenly lost the ability to produce GTP, what might happen to its signaling system?