A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?
A) DNA polymerase
B) DNA ligase
C) nucleotides
D) Okazaki fragments
E) primase

Question

Quizplus · Accepted Answer

The presence of Okazaki fragments indicates that the DNA replication initiated but was not completed. The fragments are created during the replication process but are joined together by DNA ligase, which seals the gaps between the Okazaki fragments. Therefore, the absence of DNA ligase from the mixture would prevent the joining of Okazaki fragments and result in incomplete replication with multiple short segments. DNA polymerase is responsible for adding nucleotides to the growing DNA strand, primase is involved in the initiation of DNA synthesis, and nucleotides are the building blocks of DNA, but their absence alone would not result in the observed replication pattern.

A Biochemist Isolates, Purifies, and Combines in a Test Tube