Final answer:
The opposite orientation of the template strand relative to the growing DNA strand is key to replication, with continuous synthesis of the leading strand and discontinuous replication of the lagging strand in Okazaki fragments, which are later connected together.
Step-by-step explanation:
The template strand for DNA synthesis indeed has the opposite orientation of the growing DNA strand, and this is crucial for DNA replication. During replication, DNA polymerase reads the template strand in the 3' to 5' direction while it adds nucleotides only in the 5' to 3' direction. This results in the leading strand being synthesized continuously in the direction of the replication fork. On the other hand, the lagging strand, which has the opposite orientation, is synthesized in Okazaki fragments that are eventually stitched together.
Okazaki fragments are short stretches of DNA replicated in the direction away from the replication fork. These fragments must be primed separately, and DNA ligase later joins them to form a continuous strand. Nucleic acid sequences are always written from the 5' end (with a free phosphate group) to the 3' end, reflecting the antiparallel nature of the two DNA strands that form the double helix.