The Sanger method of DNA sequencing uses a mixture of dNTPs and ddNTPs, which are missing oxygen atoms at both the 2' and 3' carbons. What is the role of the ddNTPs?

A.

They stop replication because they are not able to bind to the growing DNA strand.

B.

They stop replication because the next nucleotide in the growing strand cannot bind to them.

C.

The enhance replication because DNA polymerase selectively adds them to the growing DNA strand.

D.

They enhance replication because they form additional hydrogen bonds with the complimentary DNA strand.

A. They stop replication because they are not able to bind to the growing DNA strand.