Why are plasmids and bacterial cells considered important tools in genetic engineering?

• A. They can naturally produce large quantities of proteins.
• B. They allow for the easy insertion and replication of foreign DNA.
• C. They are resistant to all forms of antibiotics.
• D. They can directly modify the DNA of eukaryotic cells.

Answer: (B)

Verified step by step guidance

1. Understand the role of plasmids in genetic engineering: Plasmids are small, circular DNA molecules found in bacteria that can replicate independently of the bacterial chromosome. They are used as vectors to insert foreign DNA into bacterial cells.
2. Recognize the importance of bacterial cells: Bacteria can rapidly reproduce, allowing for the amplification of plasmids and the foreign DNA they carry. This makes them efficient tools for cloning and producing large quantities of DNA or proteins.
3. Learn about the process of transformation: Transformation is the method by which foreign DNA is introduced into bacterial cells. Plasmids can be engineered to carry specific genes, which are then inserted into bacteria through transformation.
4. Explore the concept of antibiotic resistance markers: Plasmids often contain antibiotic resistance genes, which are used as markers to identify successfully transformed bacterial cells. Only bacteria that have taken up the plasmid will survive in the presence of the antibiotic.
5. Understand the limitations: While plasmids and bacterial cells are useful for inserting and replicating foreign DNA, they do not directly modify the DNA of eukaryotic cells. This process requires additional techniques such as transfection or viral vectors.