Question

DNA replication proceeds in only one direction. Which direction is this, and why is strand elongation only possible in one direction?
A) 3' to 5'; Due to the presence of DNA polymerase
B) 5' to 3'; Due to the presence of DNA polymerase
C) 3' to 5'; Due to the presence of RNA polymerase
D) 5' to 3'; Due to the presence of RNA polymerase

Answer 1

B) 5' to 3'; Due to the presence of DNA polymerase

DNA replication proceeds in the 5' to 3' direction. This is because DNA polymerase can only add nucleotides to the 3' end of the growing DNA strand. As a result, the new strand can only elongate in the 5' to 3' direction.