Variable number tandem repeats (VNTRs) are repeating DNA sequence...

Question

Variable number tandem repeats (VNTRs) are repeating DNA sequences of about 15–100 bp in length, found both within and between genes. Why are they commonly used in forensics?

Accepted Answer

Welcome back. Here's our next problem. It says blank are sequences with repeating units ranging in length from 7-100 base pairs. Whereas blank have repeating units with a length of 1-6 base pairs. And when we look over our answer choices we see we kind of have three terms that are mixed up in different orders as our different choices short tandem repeats, satellite D. N. A. And variable number tandem repeats. Well these repeating units um in the sequences that has said we have choices between 1-6 base pairs or 7-100 base pairs are called Tandem repeats. And there are two types of them. And these tandem repeats of DNA sequences have these two types variable length, sometimes abbreviation abbreviated Vien tr, variable number tandem repeats between seven and 100 base pairs and then short tandem repeats sTR. Of 1 to 6 base pairs. So with that in mind we can look for answer choice. We know the first blank 7 100 must be the variable number tandem repeats. So we see that choice b. And choice d have that as their first term. And so we can eliminate choice A. And Choice C. Has short tandem repeats. First C. Has satellite D. N. A. And then we want our second space to be short tandem repeats and we find that in choice B. But not choice D. So we know that choice B is our correct answer and choice D. Can be eliminated. We C. We also that term satellite D. N. A. And satellite D. N. A. Consists of D. N. A sequences including several thousands of base pairs of very repetitive DNA. So just huge segments of very repetitive D. N. A. And it's the main component of hetero chroma tin, that densely packed form of protein that has very few genes and is not transcribed. So that's what satellite D. N. A. Is. And it's not one of these two things. So Choice B. Variable number tandem repeats are sequences with repeating units from 7 to 100 base pairs, whereas short tandem repeats have repeating units of 1 to 6 base pairs. See you in the next video.

Variable number tandem repeats (VNTRs) are repeating DNA sequences of about 15–100 bp in length, found both within and between genes. Why are they commonly used in forensics?

Key Concepts

Variable Number Tandem Repeats (VNTRs)

Forensic DNA Analysis

Genetic Polymorphism

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