A plasmid without a selectable marker was chosen as vector for cloning a gene. How does this affect the experiment?

Explanation

**Step-by-Step Solution:**

1. **Understanding Selectable Markers**: Selectable markers are genes that are included in a plasmid vector to allow for the identification of successfully transformed cells. These markers typically provide resistance to antibiotics or toxins.

2. **Role of Selectable Markers in Cloning**: When a plasmid containing a selectable marker is introduced into a host organism (like bacteria), only those cells that have successfully taken up the plasmid will survive when grown on a medium containing the corresponding antibiotic or toxin. This allows researchers to easily identify which cells have been transformed.

3. **Effect of Using a Plasmid Without a Selectable Marker**: If a plasmid without a selectable marker is used, there will be no way to differentiate between cells that have taken up the plasmid (transformants) and those that have not (non-transformants). As a result, when the cells are cultured, both types will grow, making it impossible to isolate and identify the cells that contain the desired gene.

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