A linear strand of DNA is 1,000 bp long. A recognition sequence for the restriction enzyme Eco R1 is located 300 base pairs (bp) from the 5' end of this linear DNA molecule. Digesting this DNA molecule with Eco RI would produce ________.
A) one DNA fragment, 1,000 bp long
B) three DNA fragments, two of them 300 bp long and one 400 bp long
C) two DNA fragments, one 300 bp long and one 700 bp long
D) two fragments, each 500 bp long
E) none of the above

Question

Quizplus · Accepted Answer

Digesting the DNA molecule with Eco RI would cut the DNA at the recognition sequence, which is 300 bp from the 5' end of the linear DNA molecule. This would produce two DNA fragments: one 300 bp long and one 700 bp long. Therefore, choice C is the correct answer.

A Linear Strand of DNA Is 1,000 Bp Long