Complementary strands of a DNA double helix have opposite chemical polarity but are synthesized in the same direction (replication fork movement).This is accounted for by:
A) Using a 3'5' polymerase to synthesize the lagging strand.
B) Using discontinuous synthesis on the leading strand.
C) Using the polymerase activity of DNA ligase.
D) Using the 5'3' polymerase activity of Pol III to synthesize multiple short segments which are later covalently joined.
E) None of these

Question

Complementary strands of a DNA double helix have opposite chemical polarity but are synthesized in the same direction (replication fork movement).This is accounted for by:
A) Using a 3'5' polymerase to synthesize the lagging strand. 
B) Using discontinuous synthesis on the leading strand. 
C) Using the polymerase activity of DNA ligase. 
D) Using the 5'3' polymerase activity of Pol III to synthesize multiple short segments which are later covalently joined. 
E) None of these

Quizplus · Accepted Answer

The 5' to 3' polymerase activity of Pol III synthesizes multiple short segments on the lagging strand, which are then covalently joined together by DNA ligase. This results in the complementary strands of the double helix being synthesized in the same direction but having opposite chemical polarity. Choices A, B, and C are incorrect because they do not explain the synthesis of complementary strands in the same direction.

Complementary Strands of a DNA Double Helix Have Opposite Chemical