Example of a van Deemter plot. The plot shows that the optimum flow rate for a given column is the net result of the influence of flow rate on longitudinal diffusion, equilibration time and multiple pathways.

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#Unit 4. Cell Communication and Cell Signaling

PI-3 kinase was first identified in studies of the 

polyoma virus, a DNA virus

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#Unit 3. Fundamental Processes

Humans have the enzyme hSMUG1, which removes any U residues that occur in single-stranded DNA during replication or transcription.  Two other human DNA glycosylases, TDG and MBD4, remove either U or T residues paired with G, generated by deamination of cytosine or 5-methylcytosine, respectively.

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#Unit 11. Evolution and Behavior

Sexual selection is selection that promotes traits that will increase an organism’s mating success.

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#Unit 3. Fundamental Processes

During initial transcription, the polymerase remains stationary on the promoter, unwinds downstream DNA, and pulls that DNA into itself

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#Unit 5. Developmental Biology

An anterior-to-posterior gradient of Bicoid protein

An anterior-to-posterior gradient of Hunchback protein