In a recombinant DNA cloning experiment, how can we determine whether DNA fragments of interest have been incorporated into plasmids and, once host cells are transformed, which cells contain recombinant DNA?

What steps make PCR a chain reaction that can produce millions of copies of a specific DNA molecule in a matter of hours without using host cells?

How has DNA-sequencing technology evolved in response to the emerging needs of genome scientists?

How can gene knockouts, transgenic animals, and gene editing techniques be used to explore gene function?

Write a short essay or sketch a diagram that provides an overview of how recombinant DNA techniques help geneticists study genes.

What roles do restriction enzymes, vectors, and host cells play in recombinant DNA studies? What role does DNA ligase perform in a DNA cloning experiment? How does the action of DNA ligase differ from the function of restriction enzymes?

The human insulin gene contains a number of sequences that are removed in the processing of the mRNA transcript. In spite of the fact that bacterial cells cannot excise these sequences from mRNA transcripts, explain how a gene like this can be cloned into a bacterial cell and produce insulin.

Although many cloning applications involve introducing recombinant DNA into bacterial host cells, many other cell types are also used as hosts for recombinant DNA. Why?

Using DNA sequencing on a cloned DNA segment, you recover the nucleotide sequence shown below. Does this segment contain a palindromic recognition sequence for a restriction enzyme? If so, what is the double-stranded sequence of the palindrome, and what enzyme would cut at this sequence?

CAGTATGGATCCCAT

Restriction sites are palindromic; that is, they read the same in the 5' to 3' direction on each strand of DNA. What is the advantage of having restriction sites organized this way?

List the advantages and disadvantages of using plasmids as cloning vectors. What advantages do BACs and YACs provide over plasmids as cloning vectors?

What are the advantages of using a restriction enzyme whose recognition site is relatively rare? When would you use such enzymes?

In 1975, the Asilomar Conference on Recombinant DNA was organized by Paul Berg, a pioneer of recombinant DNA technology, at a conference center at Asilomar State Beach in California. Physicians, scientists, lawyers, ethicists, and others gathered to draft guidelines for safe applications of recombinant DNA technology. These general guidelines were adopted by the federal government and are still in practice today. Consider the implications of recombinant DNA as a new technology. What concerns might the scientific community have had then about recombinant DNA technology? Might those same concerns exist today?

In the context of recombinant DNA technology, of what use is a probe?