A _____ is a single-stranded DNA molecule used in hybridization reactions to detect the presence of a particular gene in an assortment of DNA fragments. (Hybridization Reactions: reactions that combine two complementary single-stranded DNA molecules)

Okay, everyone. A blank is a single stranded DNA molecule used in hybridization reactions to detect the presence of a particular gene in an assortment of DNA fragments. And the note here is that hybridization reactions are reactions that combine 2 complementary single stranded DNA molecules. Okay. So we're looking for a particular thing, which is a single stranded DNA molecule used in these hybridization reactions that detect particular DNA sequences. Remember that these are going to be probes. The correct answer is answer choice Probes are going to be small sequences of DNA made by a scientist. So, for example, let's say the scientist wants to see if you have a particular gene. They will take a blood sample or a tissue sample or something like that. They will put your DNA into a southern blot, and they will take a probe that is the complimentary sequence to the gene that they're looking for. And they'll put it in that southern blot with your DNA. If the probe binds to your DNA, you have the gene that they're looking for. This is a hybridization reaction because the probe binds with your DNA, and it tells the scientists that you have the gene if it binds to your DNA. If it doesn't, you don't have that gene. So the correct answer here is answer choice c. A probe is a single stranded DNA molecule used in hybridization reactions to detect the presence of a particular gene in an assortment of DNA fragments. And all of this is done in the Southern Blotting Technique. Okay, everyone. Let's move on to our next video.