[Campbell Biology P.469] According to Figure 20.6 b and the accompanying text, what do the p... | Practice Question

According to Figure 20.6 b and the accompanying text, what do the pink bands observed in a gel electrophoresis experiment represent?

  • A: Individual DNA molecules of varying lengths.
  • B: Thousands of DNA molecules of the same length.
  • C: Proteins separated by electrical charge.
  • D: RNA molecules that have hybridized to the gel.

Explanation

According to the text accompanying Figure 20.6 b , after the current is turned off and a DNA-binding dye is added, 'Each pink band corresponds to many thousands of DNA molecules of the same length.' This indicates that the bands are visible aggregations of DNA fragments that have traveled to the same position due to their identical length.