Question

DdNTPs are used in the Sanger method of sequencing to ______ DNA synthesis at particular positions.

1) initiate
2) terminate
3) elongate
4) disrupt

Answer 1

The ddNTPs are used in the Sanger method of sequencing to terminate DNA synthesis at particular positions.

Step-by-step explanation:

The ddNTPs (dideoxynucleotides) are used in the Sanger method of sequencing to terminate DNA synthesis at particular positions.

The ddNTPs lack a free 3' OH group needed to add another nucleotide, so when a ddNTP is incorporated into a growing DNA strand, the chain can no longer be extended.

By utilizing a predetermined ratio of regular deoxynucleotides to dideoxynucleotides, different sized DNA fragments can be generated for sequencing.