What is 'semi- conservative' DNA replication ? How was it experimentally proved and by whom ?

Explanation

### Step-by-Step Solution

**Step 1: Understanding Semi-Conservative DNA Replication**
- Semi-conservative DNA replication is a process in which each strand of the original DNA molecule serves as a template for the synthesis of a new complementary strand. This means that when DNA replicates, each new double helix consists of one old (parental) strand and one newly synthesized strand.

**Step 2: The Experiment by Meselson and Stahl**
- The concept of semi-conservative replication was experimentally proven by scientists Matthew Meselson and Franklin Stahl in 1958. They designed an experiment using E. coli bacteria to demonstrate how DNA replicates.

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