The results shown are from a DNA test for four genes used in a pa...

Question

The results shown are from a DNA test for four genes used in a paternity identification case. DNA for the mother (M) and her child (C) are shown along with DNA from two possible fathers, F1 and F2.

What can you conclude based on the DNA results available?

Accepted Answer

Hi, everyone. Welcome back. Let's look at our next question. What is the result if the alleged father is excluded as the biological father based on S T R analysis? To I say the alleged father is confirmed as the biological father. B, the biological father is unknown c the alleged father is not the biological father or choice. D the mother is confirmed as the biological mother. So let's remember what S T R analysis is. Let's looking at alleles that are categorized by the number of repeats of short DNA sequences and you can compare the number of repeats on the child's chromosomes to the mother's and potential fathers chromosomes. So basically, you're looking at the two alleles that the child has and you should be able to see that those were inherited from the parents. So one will be inherited from the known mother and the other needs to have been inherited from the father. And the principle behind excluding someone as a biological father is that a child cannot inherit and a, an alley that the parent does not have. So if when you look at the child's genotype, you see an alley that is not seen in the father's genotype, then you can rule out that person as the biological father. And this can be done with a very high degree of competence. So if the father is excluded as the biological father, just based on this S T R analysis, then the result would be choice. C the alleged father is not the biological father. Now, it is important to note this doesn't count as definitive proof. You need to take into account other factors like the timing of conception, um the potential for some sort of uh something going wrong with the testing and it, but it does provide a high degree of certainty. Let's look at our other answer choices to understand why they're not our answers. Choice. A the alleged father is confirmed as the biological father. Well, that one's pretty obviously not our correct answer to B the biological father is unknown. Well, this may be the case but all that the S T R analysis shows you is that this particular person is excluded as the father. You would then look at other potential candidates, perhaps close biological relatives. Um But you could find a candidate another way then choice D the mother is confirmed as the biological mother. Well, you already would have looked at the mother's genotype as part of this analysis because you would expect the child to have one alley inherited from each parent. So this doesn't really mean anything in choice. D because you already have the mother's DNA for comparison. You're looking to see that second all wasn't inherited from the alleged father. So again, our answer to the result, if the alleged father is excluded as the biological father based on S T R analysis choice C, the alleged father is not the biological father. See you in the next video.

The results shown are from a DNA test for four genes used in a paternity identification case. DNA for the mother (M) and her child (C) are shown along with DNA from two possible fathers, F1 and F2. What can you conclude based on the DNA results available?

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