What are the short DNA segments produced on the lagging strand that are later joined to form a complete strand?

• A. Okazaki fragments
• B. Nucleotide
• C. Hydrogen bond
• D. Purines

Answer: (A)

During DNA replication, the strands run in opposite directions, and DNA polymerase can only synthesize in the 5' to 3' direction. This means the lagging strand is copied discontinuously as short segments instead of one continuous piece. These short segments are called Okazaki fragments. Each fragment starts with an RNA primer laid down by primase, and DNA polymerase extends from the primer to build DNA. When the entire lagging strand is finished, the RNA primers are removed and replaced with DNA, and DNA ligase seals the gaps to form a continuous strand. The other options refer to a single nucleotide, a type of bond between bases, or a class of bases, not the short, later-joined segments produced on the lagging strand.