Genes & Alleles

In this video, we're going to briefly introduce jeans and a Leal's and so jeans air defined as small segments of D N A. That are going to encode very specific proteins. And these proteins can go on to lead to the expression of a specific trait. And so, for example, there could be a gene for eye color. And of course, because this is a gene, it means that it's a small segment of DNA, and it's going to code for a very specific protein in this protein, in this case is going to lead to the expression of a very specific trait or a very specific eye color. Now, of course, we know that people can have different eye colors. Some people have blue eyes, some people have brown eyes. And so, of course, this means that there could be different versions of genes, so there can be a gene for eye color. But there could be different versions of the gene for eye color, and this is what scientists refer to as Ah Leal's and so Leo's air defined as alternative or different versions of specific genes. And so once again, there can be a gene for eye color, but there could be different versions of the gene for eye color. There could be a version of the gene for eye color. That's a gene for blue eyes, and there could be another version of the gene for eye color. That's the gene for brown eyes. And so the blue eye and brown eyes represent alternative or different versions of the gene for eye color. And so the blue eye and brown I represent different Khalil's. Now it's important to note moving forward in our course that Ah Leal's are typically represented using capital and or lower case letters now moving forward in our course in a different video, we'll talk Maura about genetics and how these different folios can interact with each other in a deployed organism. But for now, just for the sake of unexamined I'll, we're saying here that perhaps the Capital Letter B could represent an alil, or specific version of a gene for blue eyes, And the lower case, Letter B could represent another alil, another version of the same gene for brown eyes. Now, if we take a look at our image down below it, the wheels for eye color, which will notice is that we're showing you these two replicated chromosomes. We have one replicated chromosome over here on the left and another replicated chromosome over here on the right hand side. And so what you'll notice is that these air replicated chromosomes because they each have, uh, to sister chromatic IDs. And so those are the two Sister Crowe motives for the left one and the two Sister Chrome is over here. Sister chromatic IDs are highlighted as you see, so we know that these are replicated chromosomes. And what's important to note is that here there are, uh, a version of a specific gene and alil represented with a capital letter. And so this would be for, for example, just gene A. And this is the capital letter version of Gene A. And notice that this chromosome over here also has the capital letter version of Gina. So these represent identical genes. Identical a Leal's. But notice for this other gene on the chromosome for be that this one over here on the left has the capital B version of this gene or the capital B alil, and this one has the lower case B version of the gene or the lower case be illegal. And so, again, just for the sake of our example, perhaps the Capital B version of the gene would represent the blue eye. Oh, Leo. And so notice that the capital be here is coding for the blue eyes, and so you can see an individual here with blue eyes. And then perhaps the lower case B represents the alil for brown eyes. So this is the brown eye khalil, and so you can see an individual here with brown eyes. And so it's these jeans and a leal's that air, really going to, uh, be responsible for a lot of the traits that organisms display. And so again, later, in our course, we'll get to talk a lot more about genetics and the combination of these a Leal's within a deployed organism. But for now, this year concludes our brief introduction to jeans and a Leal's, and we'll be able to talk Mawr and Maura about these as we talk about my oh sis moving forward in our chapter. So I'll see you all in our next video

and this video, we're going to distinguish between Hap Lloyd and deployed cells. But first we need to define the term sell ploy T, and so sell Employee is defined as the number of copies or sets of specific genes or chromosomes found in a cell. And so when it comes to sell Ploy D, for the purposes of this course, there are really two specific terms that you should be familiar with, and we have the number down below number one and number two. And so the very first term that you should know is Hap Lloyd and Half Lloyd is commonly symbolized with the letter, and and so Hap Lloyd cells are going to be cells that only have one copy of each gene or chromosome. Now, the second term that you should know is deployed, and the term deployed is commonly abbreviated. Using the symbol to and and so deployed basically means that the cells going toe have two copies of each gene or chromosome. And of these two copies, one of the copies is going to be inherited from each of the parents. One copy would be inherited from the mother, and the other copy would be inherited from the father. And so one way that helps me remember the difference between Hap Lloyd and deployed is that the root die here and deployed as a route that means to. And so DYP Lloyd or deployed here means that it's going to have two copies of every gene or chromosome. And of course, the root Hap Lloyd has this route hat here, which can remind you of the hat and the word half. And so Hap Lloyd cells are going to have half the number of chromosomes as deployed cells. So they have one copy of each gene or chromosome instead of having two copies of each gene or chromosome. And so, if we take a look at our image down below, we can further distinguish between Hap Lloyd and deployed cells. And so notice over here on the left hand side, we're showing you Ah hap Lloyd Cell and Hap Lloyd is commonly abbreviated with just the letter end. And so which will notice is that the Hap Witsel has one copy of the tall chromosome and one copy of the short chromosome, so it really only has one copy of each chromosome and of course, there are genes on the chromosome, so it's only gonna have one copy of each gene. And so here is a half Floyd cell with again one copy of the tall chromosome in blue and one copy of the short chromosome here in reddish color. Now, if we compare that to the deployed cell over here on the right hand side again deployed is commonly abbreviated with the symbol to n, uh noticed that there are two copies of the tall chromosome. There's one copy here in blue inherited from the father. And there's another copy of the tall chromosome inherited from the mother here. Uh, so there are two copies of the tall chromosome and then notice that there are also two copies of the short chromosome. There's one copy of the short chromosome here in blue, inherited from the father and one copy of the short chromosome. Uh, reddish pink here, inherited from the mother. And so there are two copies of every chromosome on. Of course, there are genes on the chromosome, so there are also two copies of every gene in the deployed cell. And so here you can see a cell on its nucleus with the deployed number of chromosomes here. And so distinguishing between Hap Lloyd and deployed cells is going to be very important as we move forward in our course and talk about my Oh, sis. So this here concludes our brief introduction to Hap Lloyd versus deployed cells, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.

Okay, everyone. Which of the following statements is true of species that has a chromosome number off to an equal 16? Okay, so first off, what do we know? What does too and stand for? Remember that to end means deployed two of each chromosome and the deployed number here is 16. So let's write that down to in equals 16. Now, what do we know about the half Lloyd cells while half Loida symbolized by simply an end? So to get in simply, divide 16 by two and you're going to get eight chromosomes. So a deployed cell of this species is gonna have 16 chromosomes and half Lloyd's cell of the species has eight chromosomes. So knowing that, let's look at her answers. Answer. Choice A. Says the species is deployed. Okay, Perfect. With 32 chromosomes, Purcell remember, the deployed number is 16. It's not 32 so that's not the answer. Answer. Choice be says each half Floyd cell of the species has chromosomes. Remember, that's not true either, because we just said down here that the half Lloyd number is eight. So that's not what we're looking for. Answer. Choice C says each deployed cell of this species has chromosomes from the father and 16 chromosomes from the mother. Well, if they're 16 from Mom and 16 from Dad in a single cell, that means there's 32 in total. And we know that can't be true because the deployed number 16, not 32. So that's not the answer we're looking for. Answer. Choice D says each deployed cell. This species has eight chromosomes from the father and eight chromosomes from the mother. Eight chromosomes from Mom, plus eight chromosomes from dad is 16 total chromosomes, which is the deployed number, which is a perfect answer. So for this mystery, species that happens toe have deployed cells with 16 chromosomes. Eight of those chromosomes air coming from Mom and eight of those chromosomes. Air coming from Dad. Okay, everyone, let's move on to our next video