Question

chain termination reactions used in automated (sanger) dna sequencing require a replication terminator that has: a 3'-h group. a reversible blocker molecule for the 3'-oh group. a binding site for reverse transcriptase. a 2'-oh group. a free 3'-oh group.

Answer 1

Chain termination reactions used in automated DNA sequencing require a reversible blocker molecule for the 3'-OH group, such as dideoxynucleotides (ddNTPs).

Step-by-step explanation:

The chain termination reactions used in automated (sanger) DNA sequencing require a replication terminator that has a reversible blocker molecule for the 3'-OH group.

The reversible blocker molecule prevents the addition of more nucleotides to the growing DNA strand, effectively terminating the replication process. In the Sanger method, dideoxynucleotides (ddNTPs) are used as the reversible blockers.

These ddNTPs lack a free 3'-OH group, preventing the addition of further nucleotides.