Final answer:
Semi-conservative replication is the process where each new DNA strand includes half of the original strand, pairing an old and a new strand in each daughter DNA molecule.
Step-by-step explanation:
The process during which each new DNA strand retains half of the original DNA strand is called semi-conservative replication. During this process, the two strands of the double helix serve as templates for the formation of new complementary strands. Each resulting DNA molecule consists of one parental, or "old", strand and one newly synthesized, or "new", strand. This ensures that the genetic information is accurately passed down to each daughter cell during cell division.