In DNA replication, each daughter duplex contains one parental (old) strand and one newly synthesized strand. This replication mode is called:

Introduction / Context:
The fundamental model of DNA duplication explains how genetic information is preserved across generations. The question asks for the name of the mode in which each daughter molecule inherits one old strand paired with one new strand.

Given Data / Assumptions:

• Double-stranded parental DNA serves as template.
• New synthesis follows base-pairing rules.
• After replication, each daughter has one old and one new strand.

Concept / Approach:
This description matches the semi-conservative model verified experimentally by Meselson and Stahl using isotopic density labeling of DNA in E. coli.

Step-by-Step Solution:
1) Each parental strand templates a new complementary strand.2) Resulting daughter duplexes are hybrid: old + new.3) Therefore, the correct term is “semi-conservative”.

Verification / Alternative check:
Density gradient centrifugation after one and two generations produced hybrid and light bands consistent with semi-conservative replication rather than conservative or dispersive models.

Why Other Options Are Wrong:
“Mutational” is not a replication mode; “discontinuous” describes lagging-strand synthesis mechanics; “antiparallel” refers to strand polarity, not the inheritance pattern.

Common Pitfalls:
Confusing mechanical terms (discontinuous) with inheritance models (semi-conservative).

Final Answer:
Semi-conservative