Explain how gene recombination leads to the production of vast nu...

Question

Explain how gene recombination leads to the production of vast numbers of different B-cell receptors.

Accepted Answer

Welcome back. Here's your next question. Which of the following happens during genetic recombination causing diversified B. Cell receptors. We're gonna focus on this word recombination and recall from our content videos what that entails and that's why we have the homologous chromosomes lined up one from either parent. They've lined up next to each other. So we've got we'll do a blue one from one parent, a red one from the other parent. And a portion of these chromosomes physically crosses over each other. Now you're gonna have in recombination you actually have the D. N. A. Is cut. It breaks at this crossover point and these two segments are swapped with each other resulting in the offspring inheriting chromosome that is not identical to the parent chromosome that it from the parent it came from. Because instead your offspring will inherit either This blue one with a little portion from the red chromosome or can inherit this red chromosome with a little portion of blue chromosome. Pretend those are equal links not including my drawing. So we have this little swapped part here and we now have new allele combinations. So let's with that in mind. Let's look at our different answer choices Choice A says the DNA molecules are separated into a single strand and will be replicated. Well that's a description of the process of replication when that double strand has to be separated to be copied but it's not describing what's happening during recombination. So it's not our answer. Joyce B says the chromosomes lined up at the center of the dividing cells. Well that's happening in meta phase of the cell division process. Not describing replication recombination. I'm sorry not describing recombination. Then we have choice C. D. N. A. Is broken and recombined to produce new allele combinations. And that is indeed what we have here. The D. N. A. Is broken at that crossover point. The new segments are recombined with the rest of the chromosome and we now have chromosomes that have new alot combinations that in case of R. B. Cell receptors you can you're now swapping genetic material, having new alleles from the other parent that can create different B cell receptors. And finally, Choice D. Says the M. RNA is spliced and rearranged into different combinations. Well this occurs in the process of a pre R. M. RNA becoming a mature M. R. N. A. As the non coding Exxon's are spliced out of the pre M. R. N. A. To make the mature M. RNA that will be ready for translation into protein but not what's happening in recombination. So again which happens during genetic recombination causing diversified B. Cell receptors. It's choice C. D. N. A. Is broken and recombined to produce new alot combinations. See you in the next video

Explain how gene recombination leads to the production of vast numbers of different B-cell receptors.

Watch next