Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? a. AAGG TTCC b. GGCC CCGG c. ACCA TGGT d. AAAA TTTT

Video transcript

Welcome back Our next question says a blank enzyme cleaves D. N. A. Into fragments at sequence specific sites. So we may recall from earlier videos that the ability to cut DNA in very specific locations is an important part of recombinant DNA technology. And just to trigger our memories. This process cleaving at specific sites involves a certain short sequence of bases within a larger piece of D. N. A. And this enzyme cuts the D. N. A. In these specific locations in that sequence. Leaving these sticky ends that can be used to put different pieces of DNA together since they will match. So let's look at our choice is to find the name of our enzyme that we're looking for. And if we're having trouble remembering, we can look at sort of parts of the words um To help maybe trigger, look at the meanings of them too. Maybe trigger our memory. So let's look at choice A choice A here is like legs, you might recall as part of the process of D. N. A replication. It's what goes along and fills in any gaps in the DNA backbone. So ligas joins together gaps. It doesn't cleave DNA. So we can eliminate choice A choice B says restriction, we might think restrict like restricted and indeed restriction enzymes cleave D. N. A. In the specific sites. So choice be restriction is correct. Just to be thorough. We look at our other answers. Choice C Healy case. Think of helix that's part of that DNA replication that unwinds the helix to replicate the DNA. So choice C. Could be eliminated and Joyce D polymerase. We look at the word polymer. Those are the enzymes that generate the polymer in DNA synthesis, D. N. A. Or RNA synthesis as well. So polymerase is not what we're looking for restriction enzymes. Choice B. R. What cleave DNA at these specific sites. Thanks for watching. See you in the next video.