ddATP,ddTTP,ddCTP,and ddGTP are labeled with red,green,yellow,and blue fluorescent dyes,respectively.A five- base read from a sequencing reaction produced the following color sequence,read by the computer: red,yellow,yellow,green,green.What is the sequence of the template DNA?
A)TGGAA
B)AAGGT
C)ACCTT
D)TTCCA

Question

Quizplus · Accepted Answer

Based on the color sequence (red, yellow, yellow, green, green), we know that the first and second bases are either A or C (since those are the only bases that produce yellow when paired with ddCTP). The third base is either G or T, since those are the only bases that produce green when paired with ddTTP. The fourth and fifth bases are either A or G, since those are the only bases that produce green when paired with ddATP. 
Therefore, the possible sequences are:
- ACGAA
- ACGGA
- CCGAA
- CCGGA
Out of these four options, only choice C (ACCTT) matches the color sequence given.

DdATP,ddTTP,ddCTP,and DdGTP Are Labeled with Red,green,yellow,and Blue Fluorescent Dyes,respectively