Complete question:
Scientists found members of a plant species they did not recognize. They wanted to determine if the unknown species was related to one or more of four known species – A, B, C, D. The relationship between species can be determined by comparing the results of gel electrophoresis of the DNA from different species. The chart below represents the results of gel electrophoresis of the DNA from the unknown plant species and the four known species.
Which two known plant species is the unknown plant species most closely related to?
Answer:
Species C is the most closely related, followed by species D.
Explanation:
Gel electrophoresis technique is used to separate different fragments of DNI, RNA, and other macromolecules or proteins, concerning their size/weight and charge.
Gel electrophoresis of DNI lets us visualize how many different fragments of the molecule are present in a sample and how they differ from each other. The presence of fragments of the same size will be distinguished as a line named band. Each band represents many DNI fragments of similar size placed in the same position. The result of the gel electrophoresis will be different bands in different positions according to their sizes. The biggest ones will not migrate in the gel as much as the smallest ones.
In the exposed example we can assume that the most closely related species is C. The second most similar is species D.
The gel electrophoresis of the DNA from the unknown plant species resulted in five different bands, which means five types of fragments of different sizes.
- Four of the five bands expressed by the unknown species coincide with the bands of species C. Species C only lack one band to be exactly the same.
- Species D coincides in three bands and lack two bands to be exactly the same as the unknown species.
- Species A only coincides in one band.
- Species B does not coincide in any band, meaning that this is the most different one
For a better understanding, look at the attached files, where you will find the chart.
