QuestionSBA
QuestionChoice
This is correct. The lack of the 3'-OH group on ddNTPs means the phosphodiester bond cannot form. Therefore, when DNA (Taq) polymerase randomly incorporates a ddNTP, DNA strand elongation ceases.
10004351
a
ddNTPs lack a hydroxyl group
QuestionChoice
This is incorrect. Taq polymerase randomly incorporates a ddNTP which lacks a hydroxyl group, leading to the ceasation of DNA strand elongation as a phosphodiester bond cannot be formed.
10004355
e
Taq polymerase reaches end of the template strand
QuestionChoice
This is incorrect. It is the lack of the hydroxyl group on the ddNTPs that is responsible for the cessation of DNA strand elongation.
10004352
b
ddNTPs lack a carboxyl group
QuestionChoice
This is incorrect. Taq polymerase randomly incorporates a ddNTP which lacks a hydroxyl group, leading to the cessation of DNA strand elongation as a phosphodiester bond cannot be formed.
10004354
d
Taq Polymerase randomly stops synthesising the strand
QuestionChoice
This is incorrect. It is the lack of the hydroxyl group on the ddNTPs that is responsible for the cessation of DNA strand elongation.
10004353
c
ddNTPs are fluorescently tagged
Concept
Chapter
2693
4272
DNA sequencing (Sanger sequencing)
Topic
212
Molecular and Cellular Basis of Health and Disease
13417
Sanger sequencing, or chain termination PCR, is a technique used for DNA sequencing.

Why does DNA strand elongation arrest during Sanger sequencing?
a