You ran an experiment in lab that produced the following gel-electrophoresis results. The smallest band recorded was 2.03 kb and the largest band recorded was 17.15 kb. Which well contained a 17.15kb fragment but not a 2.03kb fragment? A. 1
B. 2
C. 3
D. 4

Gel-electrophoresis separate macromolecules according to their size and charge. In the exposed example, the well that contains a 17.15kb fragment but not a 2.03kb fragment is number 2 (Option B) (based on the attached image).

Gel-electrophoresis is a technique widely used in labs to separate macromolecules, like DNA, RNA, and proteins.

This technique is based on the size and charge of the molecules. It expresses a pattern of differentiation according to the length of the fragments.

Once placed in the gel, molecules start their migration. Smaller molecules will travel faster and farther than the bigger ones.

So whenever we see a gel-electrophoresis result, we know that the largest fragments are placed in the first position, while the smallest ones are in the last position.

In the exposed example, we know that the smallest fragment is 2.03kb, while the largest one is 17.15kb.

We assume that largest fragment will be placed in the first position, and the smallest one will be placed in the last position.

We need to find a well that has fragments of 17.15 kb but not fragments of 2.03 kb.

So let us find the well in which there are molecules in the first position but not in the last one.

Note: In the attached files, you will find a gel-electrophoresis result image on which I base my answer. If this image is different from yours, choose the correct well in your gel-electrophoresis following the same reasoning.

The correct well is Two (Option B). Molecules have migrated to the first position but not to the last one.

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C

Explanation:

the fossil record provides evidence of a common ancestor to many species.