The gel presented here shows the pattern of bands of fragments produced with several restriction enzymes. The enzymes used are identified above the lanes of the gel, and six possible restriction maps are shown in the column to the right.

One of the six restriction maps shown is consistent with the pattern of bands shown in the gel.

From your analysis of the pattern of bands on the gel, select the correct restriction map and explain your reasoning. <>.

Key Concepts

Restriction Enzymes

Restriction enzymes, or restriction endonucleases, are proteins that cut DNA at specific sequences, creating fragments of varying lengths. Each enzyme recognizes a unique sequence of nucleotides, allowing for precise manipulation of DNA. Understanding how these enzymes work is crucial for interpreting the banding patterns on a gel, as the size and number of fragments produced depend on the specific enzyme used.

Gel Electrophoresis

Gel electrophoresis is a laboratory technique used to separate DNA fragments based on their size. When an electric current is applied, smaller fragments move faster through the gel matrix than larger ones, resulting in distinct bands. Analyzing the distance each band travels allows researchers to infer the sizes of the DNA fragments, which is essential for matching the observed pattern to the correct restriction map.

Restriction Maps

A restriction map is a diagram that shows the locations of restriction enzyme cut sites within a DNA sequence. It provides a visual representation of how a DNA molecule will be fragmented by specific enzymes. By comparing the banding pattern from gel electrophoresis to the possible restriction maps, one can determine which map corresponds to the observed fragments, aiding in the identification of the DNA sequence being analyzed.