#Question id: 160
#Unit 1. Molecules and their Interaction Relevant to Biology
Of the 20 standard amino acids, only ___________ is not optically active. The reason is that its side chain ___________.
#Question id: 1928
#Unit 4. Cell Communication and Cell Signaling
Which of the following is a type of tumor that is NOT derived from hematopoietic cells?
#Question id: 26900
#Unit 10. Ecological Principles
Tundra is___
#Question id: 1386
#Unit 4. Cell Communication and Cell Signaling
The ability of a population of fibroblasts to migrate along the surface of a tissue culture dish depends on adhesion between the cell surface and the extracellular matrix molecules coating the dish. The dish is coated with laminin, and the only cell-surface protein capable of binding laminin is a cell-adhesion protein called an integrin. Integrins are integral plasma-membrane proteins that function as heterodimers. Under these conditions the rate at which a fibroblast can migrate along the laminin coated culture dish is proportional to the strength of adhesion between the cell and the laminin substrate. The table below lists the rate of cell migration observed for fibroblasts genetically engineered to generate the indicated phenotypes. One explanation for the effect of overexpression of the cytoplasmic domain of the integrin beta subunit is that this domain normally functions to bind a cytoplasmic factor necessary for integrin function. Which of the following would be the most informative experiment to identify the cytoplasmic factor?
#Question id: 31056
#Unit 4. Cell Communication and Cell Signaling