Question

In gel electrophoresis a DNA sample from an unknown donor is placed in a small well at one end of a special gel-coated plate. Samples from known donors are placed in other wells on the plate. An electric current is passed through the plate, causing the DNA fragments to separate. The size and location of the separated fragments can be compared for similarities. The more
similar the locations and sizes of the fragments, the more closely the donors of the samples are related. The diagram shows four samples being compared with an unknown sample.

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The donor of which sample is most closely related to the donor of the unknown sample?
A
Sample 1
B
Sample 2
C
Sample 3
D
Sample 4

Answer 1

I can’t see the diagram you referenced. Please either upload the gel image or describe the band patterns (for each lane list the band positions from top to bottom).

If you want to decide it yourself, follow these steps:
- Line up the lanes so the wells at the top are level.
- Compare the unknown lane to each known sample lane and count how many bands match in position (same vertical location).
- The donor most closely related is the sample with the most matching bands (exact position matches). If one sample’s band pattern is identical to the unknown, that is the closest match.

Send the image or the band-position lists and I’ll pick which sample (A–D) matches.