Question

What would be the most likely reason to use a low copy number plasmid as an expression vector during an experiment?

A. Carrying too many copies of plasmids will be a waste for the bacterial cells.
B. The replication of low copy number plasmids is tightly controlled, which will ensure the quality of expression of proteins.
C. The bacterial cells are forced to produce unwanted protein products, which could be deleterious and kill them.
D. There might be some spontaneous errors when the plasmid is being replicate, so using a plasmid with limited replication will prevent a rise of genetic mutation of the gene within the plasmid.

Answer 1

The preferred choice for using a low copy number plasmid is option B, as it allows for tight control of the replication of plasmids, ensuring regulated and high-quality protein expression, avoiding potential toxicity to the host bacteria.

Step-by-step explanation:

The correct option is B:

The most likely reason to use a low copy number plasmid as an expression vector during an experiment is B. The replication of low copy number plasmids is tightly controlled, which will ensure the quality of expression of proteins. This is because low copy number plasmids can help in managing the expression levels of the protein encoded by the plasmid, reducing the potential for the production of proteins to levels that could be harmful to the host bacteria.

In molecular cloning, molecular cloning is the process by which scientists create multiple copies of specific segments of DNA that they want to work with or study. Plasmids, serving as vectors, carry the foreign DNA fragment and ensure its replication within the bacterial host. As biotechnological tools, plasmids have key features such as antibiotic resistance markers and multiple cloning sites, making them highly versatile and useful in various applications. However, using a high copy number plasmid can sometimes lead to detrimental effects on the host cell due to overproduction of the foreign protein, which can be toxic or disruptive to the cell's normal functions. Therefore, using a low copy number plasmid can mitigate these risks by limiting the number of plasmid copies and consequently the level of protein expressed.