A DNA sequence has been cut into the following four overlapping sequence fragments:
(1) AGGGGCCTATAGCATACGTACA
(2) CGTACATCTGAGGGTACGATCATGGC
(3) CATGGCTAGCAAACGCGATCCCAAG
(4) AGGCTAGTTACGATATAGGGGCC
What is the correct order of these fragments?
A) 1, 2, 3, 4
B) 1, 3, 2, 4
C) 2, 3, 1, 4
D) 4, 1, 2, 3
E) 4, 1, 3, 2

Question

A DNA sequence has been cut into the following four overlapping sequence fragments: 
(1) AGGGGCCTATAGCATACGTACA
(2) CGTACATCTGAGGGTACGATCATGGC
(3) CATGGCTAGCAAACGCGATCCCAAG
(4) AGGCTAGTTACGATATAGGGGCC
What is the correct order of these fragments?
A) 1, 2, 3, 4
B) 1, 3, 2, 4
C) 2, 3, 1, 4
D) 4, 1, 2, 3
E) 4, 1, 3, 2

Quizplus · Accepted Answer

The correct order is determined by finding overlaps between the ends of one fragment and the beginnings of another. Fragment 4 ends with "AGGGGCC" which overlaps with the beginning of Fragment 1 "AGGGGCCT...". The end of Fragment 1 "ACGTACA" overlaps with the beginning of Fragment 2 "CGTACAT...". Finally, the end of Fragment 2 "ATGGC" overlaps with the beginning of Fragment 3 "CATGGC...". Therefore, the correct order is 4, 1, 2, 3.

A DNA Sequence Has Been Cut into the Following Four