In biotechnology what does vector means:

Options

A. An extra chromosomal DNA that replicates autonomously
B. Carrier of disease
C. Plasmid that can transfer gene to host cell
D. Selectable markers

Answer

### Step-by-Step Solution:

1. **Definition of Vector in Biotechnology**:
In biotechnology, a vector is defined as a vehicle that is used to transfer genetic material from one organism to another. The most common types of vectors are plasmids and bacteriophages.

2. **Types of Vectors**:
- **Plasmids**: These are small, circular pieces of DNA that exist independently of chromosomal DNA in bacteria. They can replicate autonomously and are often used to carry foreign DNA into host cells.
- **Bacteriophages**: These are viruses that infect bacteria and can also be used as vectors to introduce foreign DNA into bacterial cells.

3. **Requirements for a Good Vector**:
A suitable vector should have certain characteristics:
- **High Copy Number**: It should be able to replicate in high numbers within the host cell.
- **Easy Linking of Foreign DNA**: The vector should allow for straightforward insertion of the desired gene or DNA fragment.
- **Selectable Markers**: It should contain genes that enable the identification of cells that have successfully taken up the vector (recombinant cells) versus those that have not (non-recombinant cells).

4. **Function of Vectors**:
Vectors play a crucial role in recombinant DNA technology by facilitating the transfer of genes from one organism to another. This is essential for various applications, including gene cloning, gene therapy, and the production of genetically modified organisms (GMOs).

5. **Conclusion**:
In summary, in biotechnology, a vector refers to plasmids or bacteriophages that are used to transfer genetic material into host cells, playing a vital role in genetic engineering and molecular biology.