Gel electrophoresis is a technique used by molecular biologists to analyze samples of DNA or proteins. DNA was collected from the scene of a crime. Gel electrophoresis was used to compare the crime scene DNA to the victim’s DNA along with the two suspects of the crime.
Figure 1 shows the gel sheet after each sample was run. Table 1 shows the distance each band traveled from the origin. The samples were run in the same gel with a DNA standard marker for comparison. Table 2 shows the results of the standard.
Figure 1. Created for Albert. All rights reserved.
Table 1
Standard (
mm
) Crime Scene (
mm
) Suspect 1 (
mm
) Suspect 2 (
mm
) Victim (
mm
)
18
29
26
29
8
23
33
29
33
18
28
34
30
34
25
34
35
32
35
30
45
47
36
47
32
47
48
48
34
Table 2
Distance (
mm
) Size of Fragment in Base Pairs (
bp
)
18
23109
23
9416
28
6557
34
4361
45
2328
47
2027
Assume that the DNA markers on the gel sheet were measured in fragment size (in
bp
) instead of distance from the origin.
If the largest DNA marker of the DNA found at the crime scene was
6112
bp
, which of the following is a possible fragment size of the largest DNA marker of Suspect 1?
Elimination Tool
Select one answer
A
6112
bp
B
8010
bp
C
23203
bp
D
4406
bp
C. 23203 bp
To determine the possible fragment size of the largest DNA marker of Suspect 1, we look at the table of fragment sizes and distances. The largest DNA marker at the crime scene was 6112 bp, which puts it between the 4361 bp and 6557 bp fragments.
To find the possible fragment size of Suspect 1, we need to find a fragment size that falls between 4361 bp and 6557 bp. The closest fragment size in the table that fits this range is 4406 bp.
Therefore, the possible fragment size of the largest DNA marker of Suspect 1 is 4406 bp.