PCR (Polymerase Chain Reaction): It is the revolutionary method developed by Kary Mullis in the 1980s. PCR is based on using the ability of DNA polymerase to synthesise new strand of DNA complementary to the offered template strand. Because DNA polymerase can add a nucleotide only onto a pre-existing 3'-OH group, it needs a primer to which it can add the first nucleotide.
How many DNA duplex are obtained from one DNA duplex after 4 cycles of PCR?

Explanation

To determine how many DNA duplexes are obtained from one DNA duplex after 4 cycles of PCR, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the PCR Process**:
- PCR involves repeated cycles of denaturation, annealing, and extension. Each cycle doubles the amount of DNA.

2. **Initial DNA Duplex**:
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