Question

Explain why linkers are needed to make a cDNA library.

A. They facilitate DNA replication
B. They connect the cDNA to the vector
C. They prevent degradation of cDNA
D. They enhance transcription

Answer 1

Linkers are essential in a cDNA library to connect the cDNA to the vector, allowing for the easy insertion and stable integration into the plasmid.

Step-by-step explanation:

Linkers are necessary for creating a cDNA library because they serve the purpose of connecting the cDNA to the vector. These linkers are short synthetic DNA sequences that are attached to the ends of the double-stranded cDNA. Once attached, they are then treated with restriction enzymes, creating sticky ends that are complementary to the ends of the plasmid vector, which has been cut with the same restriction enzyme. This allows for the easy insertion of the cDNA into the plasmid, facilitating recombination between the two. DNA ligase then seals the nicks, creating a stable structure that can be inserted into host cells for replication and the creation of multiple copies of the cDNA.