You are interpreting data on a DNA chip or microarray. You expose the chip to a mixture of two cDNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls; labeled with a red fluorescent dye)and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labeled with green fluorescent dye). You look at a spot on the chip representing the gene for phosphofructokinase, a gene that is not affected by glucocorticoid treatment, but is instead expressed in all cells. What color should the spot representing the phosphofructokinase gene be?
A)red
B)green
C)yellow
D)no color, the spot is not labeled
E)brown

Question

Quizplus · Accepted Answer

Since phosphofructokinase is expressed in all cells and is not affected by glucocorticoid treatment, both the untreated (red) and treated (green) cDNA populations will bind to the spot. When red and green are mixed, the resulting color is yellow, indicating equal expression from both cell populations.

You Are Interpreting Data on a DNA Chip or Microarray