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: 11507

#Unit 9. Diversity of Life Forms

Which two genera have members that can evade the human immune system by frequently changing their surface proteins?

1.  Plasmodium

2.  Trichomonas

3.  Paramecium

4.  Trypanosoma

5.  Entamoeba

#Question id: 1447

#Unit 4. Cell Communication and Cell Signaling

A patient with B cell leukemia donates some cancer cells for analysis. The cells do not contain the usual chromosomal translocations associated with leukemia. Instead, a sporadic mutation seems to have arisen in a certain gene, followed by loss of heterozygosity in the second copy. This gene product is most likely:

#Question id: 4900

#Unit 8. Inheritance Biology

The chlorophyll-deficient types occur in a particular plant species due to a mutation in the DNA of the chloroplast itself, Female cytoplasm chlorophyll-deficient organisms crossed with male normal chlorophyll will produce progeny

#Question id: 1815

#Unit 4. Cell Communication and Cell Signaling

Genuine adaptive T- and B-cell responses are seen in:

#Question id: 10766

#Unit 8. Inheritance Biology