Most organisms display a circadian rhythm, a cycling of biologica...

Question

Most organisms display a circadian rhythm, a cycling of biological processes that is roughly synchronized with day length (e.g., jet lag occurs in humans when rapid movement between time zones causes established circadian rhythms to be out of synch with daylight hours). In Drosophila, pupae eclose (emerge as adults after metamorphosis) at dawn.

In each case, how would you clone the genes you identified by mutation?

Accepted Answer

Hey, everybody. Let's look at our next question. PC R amplification can be used to obtain the DNA sequence of the circadian rhythm gene in Drosophila. Which of the following statements is true regarding the cloning of a gene using this technique choice. A PC R amplification can generate a full length gene sequence without the need for cloning choice. B PC R amplification can generate a full length gene sequence that can be directly inserted into a plasmid vector. Choice C PC R amplification can generate a partial gene sequence that needs to be cloned into a plasma vector for further manipulation. DPC R amplification cannot be used for cloning genes. Well, when we recall the process of a cloning of a gene, we can think of the various steps along the way. And you have first, you've selected the gene that you want to target and then you have amplification with PC R. In this case, you amplify a DNA sequence bracketed by primers because primers have to be used in that PC R process, we can recall to sort of select the area that will be amplified in general. This is a partial gene unless you had a very small gene because PC R can only amplify DNA segments of a certain length. There's kind of a limit to the faithfulness with which it's able to reproduce a long DNA sequence. And then finally, the DNA that's been amplified. Now, you have a larger quantity of it by PC R is inserted into a plasmid and from there cloned into whatever organism you're going to use to express it. So we can kind of look at this process to evaluate our answer choices. So when we look at choice A, it says PC R amplification can generate a full length gene sequence without the need for cloning. Well, this is not correct PC R, as we said, will generally only produce a partial segment of a gene and it needs to be cloned into a vector. So that's why choice A is not correct. Choice. B says PC R amplification can generate a full length gene sequence that can be directly inserted into a plasmin vector. Well, this answer choice has the bit about needing to insert a plasmid, insert the DNA into a plasmid. But as we said, PC R is generally limited to partial gene sequences. So that's why choice B is incorrect. Choy C says PC R amplification can generate a partial sequence gene sequence that needs to be cloned into a plasma vector for further manipulation. And this is the correct description of how PC R amplification is a part of that cloning process. Then finally, choice D says PC R amplification cannot be used for cloning genes. And of course, this one is easy to eliminate as it's a very important part in terms of getting significant amounts of the DNA you're desiring to clone. So again, which of the following statements is true regarding the cloning of a gene, using the technique of PC R amplification. Choice C it can generate a partial gene sequence that needs to be cloned into a plasma vector. For further manipulation. See you in the next video.

Key Concepts

Circadian Rhythm

Gene Cloning

Drosophila as a Model Organism

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