Thursday, June 25, 2009

variation in a population


05.05.09. When only tens or hundreds of copies of a particular protein are produced in a cell, there can be large variation in the exact number per cell in a population of cells. Such variability can cause phenotypic differences among cells, even when they are genetically identical (see, e.g., Elowitz et al, Science, 2002). A histogram provides a nice way to visualize variability, as well as such staples of seventh grade statistics as mean, median, mode, and range. Students learned about histograms in the context of cell populations, then produced their own histograms from height measurements of all students in the class.