If you were to compare your genome sequence with that of your parents, how would it differ? If you were to compare your genome sequence with another student's in the class, how would it differ? What additional difference might you see if your genome was compared with that of a sub-Saharan African, or if you are of sub-Saharan African descent, with that of a non-African?

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Welcome back, everyone. Here's the next question in research comparing the genome of Children with the genome of their parents. It was found that the genome of offspring shows certain unique differences from their parents despite certain similarities, what are the main reasons for these differences? Choice? A differences in environmental exposures? Choice B, differences in lifestyle choices, choice, C, genetic recombination and spontaneous mutations or choice D epigenetic modifications. When we think about differences between the genome of Children and their parents. So why isn't it just directly? It's exactly the same half of it is exactly the same as the paternal DNA? Half of it is exactly the same as the maternal DNA. And what is the main reason? So again, we look at that word mean, so not every reason or any reason because all of our answer choices represent uh factors that might cause the genome of Children to be different. But what's the main reason that would cause the differences? Well, a big one and we think about the benefits of sexual reproduction is genetic recombination where we actually can have this crossing over and mixing up of paternal and maternal chromosomes. So instead of just directly having, you know, one copy of chromosome one from mom, one copy of chromosome one from dad. Exactly the same as the parental chromosomes. They can cross over and swap pieces. Now, the child has a chromosome one that's mostly maternal DNA with a little bit of paternal DNA and vice versa. So that would be a main reason why you'd see these differences because you're actually having recombination of the chromosomes of the parents. In addition, you can have spontaneous mutations, a child might develop a mutation in their DNA that's not inherited from either parent, but has arisen in a new way in that child that can then be passed on to future generations, but has started with that child. So choice C is going to be our answer here. When we look at all these other things, choice, a differences in environmental exposures that might modify DNA, differences in lifestyle choices. Those aren't going to affect um DNA in a major way, but can have some impact in terms of damage to DNA that might occur because of these things. So if you looked at an adult and compared their genotype to their parents, you might have modifications to their DNA. But that will be a minor factor compared to genetic recombination and mutation. And the same with choice, the epigenetic modifications, addition of things like methyl groups, uh which might be different uh given like in utero conditions, for example, in a child versus a parent. But again, the effect of those sorts of changes will be small compared to these major effects in choice c of genetic recombination and spontaneous mutations. See you in the next video.

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Key Concepts

Genetic Inheritance and Variation

Genetic Diversity Among Individuals

Population Genetics and Ancestral Differences