What is an outcome of genetic recombination? a. the synapsing of homologs during prophase of meiosis I b. the new combination of maternal and paternal chromosome segments that results when homologs cross over c. the new combinations of chromosome segments that result when self-fertilization occurs d. the combination of a haploid phase and a diploid phase in a life cycle

Video transcript

Welcome back. Our next question says what could be causing the large differences in various traits between you and your sibling? Well, we think about siblings and what they inherit. Obviously each sibling inherits half of their DNA from each parent and the siblings have the same parents. So what is responsible for large differences between siblings? Despite having the same sources for their D. N. A. Well, the answer is that when the parental chromosomes pair up and reproduction you have the phenomenon of recombination, these chromosomes come next to each other and some of them are going to have occasions where they have crossover events and they actually swap pieces of the chromosome. In this case you have one chromosome from each parent. So now instead of just inheriting this chromosome here from your father as an identical copy of his chromosome number. Whatever it is, you now have a chromosome that's mostly material from your father but has a few genes from your mother as well. So this recombination allows a huge variety of different combinations of the parental genes to be inherited by the siblings. So this greatly increases the number of combinations possible of inherited genes. So again that's recombination making this possible. So let's look over at our answer choices while we see that choice B is genetic recombination. So we know that's what we're looking for. But to be thorough. Well, just look at the other answers and see why they're not correct choice A says different chromosome numbers. Well, aside from a chromosomal disorder, we wouldn't expect siblings to have different chromosome numbers with reproduction going as it should. All human beings should have the same number of chromosomes. So that would not be a source of normal differences between siblings. Choice C says gene deletion. Again, that would be a chromosome, a genetic disorder that would be inherited um So that could create a difference if one sibling had a gene deleted and the other didn't. But that wouldn't be the source of large differences that occur on a normal basis between siblings. So Choice C. Not a correct answer. And finally, D Choice D. Says genetic mutation again, a mutation that only one sibling has would be a genetic difference, but that would be a single difference as opposed to the many differences that become possible because of genetic recombination. So, choice d not our answer. So what is it that causes large differences in various traits between you and your sibling? That would be choice be genetic recombination. See you in the next video.