Extrachromosomal DNA of bacteria used as vector in gene cloning is ________

Explanation

**Step-by-Step Solution:**

1. **Understanding Extrachromosomal DNA**: Extrachromosomal DNA refers to any DNA that exists outside the chromosomal DNA within a cell. In bacteria, this type of DNA is often found in the form of plasmids.

2. **Identifying the Role of Plasmids**: Plasmids are small, circular pieces of DNA that can replicate independently of the chromosomal DNA. They are commonly found in bacteria and can carry genes that provide beneficial traits, such as antibiotic resistance.

3. **Plasmids as Vectors**: In the context of gene cloning, plasmids serve as vectors. A vector is a vehicle used to transfer genetic material into a host organism. Plasmids can be engineered to carry specific genes of interest, making them essential tools in recombinant DNA technology.

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