A small portion of the human transport protein amino acid sequence is shown here. The upper sequence is associated with darker skin, and the lower sequence is associated with lighter skin. What DNA base-pair change created the light-skin form of the human protein from the gene that coded for the dark-skin form?

Video transcript

Hello everyone here we have a question telling us that a green parakeet gave birth to five young birds, four of which were green and one of which was yellow. The researcher determined the amino acid sequence for both enzymes responsible for green and yellow pigment production and found the following result. Green A L A G L Y V A L A L A P R O T H R G L Y L E. U. And yellow A L A G L Y V A L A L A T H R th R G L Y L E. U. And our goal here is to identify which DNA base pair change resulted in the L. Pillard parakeet. So if we look at these, we see that a P. R. O. It's changed to a thr This means that there must have been altered from A C. In the first position to an A. In the first position. The base pair change therefore must have been from a C. G. Base pair change to an A. T. Base pair, change in the D. N. A. Coding for the first position of the code on. So our answer here is BC. G 2 80. Thank you for watching. Bye.