After a double digest with EcoRI and HindIII, a gel electrophoresis shows that you have several restriction fragment bands. You see bands of lengths 3kb, 4kb and 5kb. From previous tests, you know that there are two EcoRI restriction sites and two HindIII restriction sites in the DNA fragment you are studying. How many restriction fragments are really in your reaction?

When performing recombinant DNA techniques, it is often necessary to cut desired DNA sequences with restriction enzymes. Where are these enzymes typically isolated from?

Which of the following DNA sequences could most likely be cleaved by an endonuclease?

Which of the following is a reason that cDNA clones of eukaryotic genes are capable of being expressed in prokaryotic cells?

I. cDNA clones do not contain any of the introns present in the genomic DNA

II. Prokaryotes have the basic translational machinery needed to express these genes

III. Prokaryotes are capable of making similar post-transcriptional modifications as eukaryotes