Identical twins each carry the same genome, but over time, can develop different phenotypes. How can you explain this?

Video transcript

Hi, everybody. Let's take a look at this practice problem together, which of the following will be different and identical mono psychotic twins. Now recall that identical Mona's psychotic twins are derived from the same zygote. So you have the combination of a male gammy and a female gammy to produce a single zygote. What happens in Mona's psychotic twins is that zygote then splits into two. So let's identify what can be different. Is it a genome now? Because they came from the same zygote, the genomes will be identical. Therefore, a is not the correct answer is the answer. C. So since mono psychotic twins have identical genomes, the sex, which is determined by both X and Y chromosomes would be identical as well. Therefore, C is not the correct answer. And we know that d all of the above is not correct either. That means that option B, effigy gnome is the correct answer. Now, the EPA genome can be different because the identical twins can have different phenotype IQ characteristics even though they have identical genomes. And this is due to epigenetic changes where you have modification of the genome without changing the nucleotide sequence itself examples of this include DNA methylation and histone assimilation. So be epi genome is the correct answer. Alright, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.