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.

 Which of the following is the most likely explanation for failure of overexpression of the integrin alpha subunit to alter the rate of fibroblast migration?

#Question id: 5204

#Unit 11. Evolution and Behavior

Bioinformatics can be used to scan sequences for probable genes looking for start and stop sites for transcription and for translation, for probable splice sites, and for sequences known to be found in other known genes. Such sequences containing these elements are called

#Question id: 5203

#Unit 11. Evolution and Behavior

The biggest problem with the shotgun technique is its tendency to underestimate the size of the genome. Which of the following might best account for this?

#Question id: 5199

#Unit 11. Evolution and Behavior

For mapping studies of genomes, most of which were far along before 2000, the 3 -stage method was often used. Which is the usual order in which the stages were performed, assuming some overlap of the three?

#Question id: 5012

#Unit 11. Evolution and Behavior

#Question id: 5014

#Unit 11. Evolution and Behavior

 Following geological time period and major evolutionary event?

I. Devonian                            A. Gymnosperms dominant

II. Jurassic                               B. Amphibians diversify; first reptiles

III. Carboniferous                  C. Mammals appear

IV. Triassic                           D. Seed plants appear

#Question id: 5015

#Unit 11. Evolution and Behavior

 During which of the following largest mass extinction recorded in the history of life on Earth.