Difference Between Genes & Alleles - Video & Lesson Transcript | cypenv.info
Deoxyribonucleic acid, or DNA, is the substance that living organisms use to store genetic information -- that is, information that an organism. What's the difference between Allele and Gene? A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more. Genes and alleles are genetic sequences, and both determine biological traits. So, what makes them different?.
One of four different nucleotide bases -- a single- or double-ringed molecule that contains nitrogen -- hangs off each sugar unit. The sequence of bases along the DNA sugar-phosphate backbone spells out the genetic code.
In most organisms, a chromosome contains two strands of DNA united in a double-helix structure in which the bases of one strand bind to those of the other.
The sequence of bases in one strand determines the sequence in the sister strand. This is because only certain bases can pair with each other.
Alleles and genes
Only some portions of a DNA strand -- the genes -- code for proteins. Chromosomes Chromosome proteins, called histones, tightly bind to the DNA double helix. This binding compresses the long DNA molecules so that they fit within a cell.
Humans contain 23 pairs of chromosomes, and if you unwound all the DNA from a human cell and placed it end to end, it would exceed six feet in length. During cell division, a cell replicates its complement of chromosomes so that each daughter sell gets the full diploid set. Sciencing Video Vault Genes and Alleles Genes appear throughout the length of each chromosome, and each chromosome pair has a unique set of genes.
You can only recognize genes from their information content -- the sequence of nucleotide bases.
Otherwise, genes are indistinguishable from the rest of the chromosome. So RNA doesn't have to only play this kind of in between messenger function. It actually can play a functional or a structural role. In fact there are theories that the earliest life, the most primitive life was nothing but self replicating RNA and then the systems became more, and more, and more complicated and complex until eventually you end up with things like redwood trees and hippopotami.
Elephants, but whatever else, but it all started with potentially self replicating RNA. Some people say it might be some type of proteins are able to replicate, who knows, but RNA is definitely, is definitely an interesting character in this. So each of these Genes they can code for a type of protein or even a functional RNA. That's what a Gene is. Now what about an Allele?
When the Allele is a specific variation of the Gene. So for example, let's say that you look at the at the same stretch of DNA. We're both human beings and we have for the most part very similar DNA.
So this is-- Actually let me straighten it out.
What’s the Difference Between a Gene and an Allele?
Now we're both human beings and most of our genetic material is fairly similar, but we might have variations in how this Gene is coded. For example, you might have or I might have a let's say, I have a an Adenine right there, but right at that exact spot you might have a different base.
You might have a, I don't know, you might have a, you might have-- Actually let me just-- You might have a Thymine right over there. So it's encoding for a protein, or you know, functional RNA that's playing the same role. Maybe it has a role in the immune system or role in your skin color or role in how your brain develops, but there's a variation.
What’s the Difference Between a Gene and an Allele? | cypenv.info
There's a variation in how it's coded. Now some of these variations which could arise through mutations, it might not have any impact in the function of the eventual protein that gets constructed. You might just have a different Amino Acid sometimes. In fact, you might not even have a different Amino Acid because many times you have two Codons coding for the same Amino Acid, but even in a case you might have one different Amino Acid in a protein that has 4, Amino Acids it doesn't change how that protein acts or how it functions.
Or sometimes it might. It might change how that protein functions.
It might change how that protein regulates other things and whoever knows whatever else, and so you could imagine that you have Genes. This Gene right over here.
Maybe it has a role in eye color, and because of this variation or because of other variations that show up in both cases they code for the protein that say regulates eye color, or regulates the amount of pigment you have, but because your variation right over here might lead or help lead-- And these things are very complex, it's very seldom do you have a gene just for this, but this might make you-- especially if you have a Gene like this from both of your parents, maybe this one would go for blue eyes.
Blue eyes, it somehow helps produce blue eyes. While this, while mine somehow helps produce brown eyes. And obviously I'd want to think about which variant of this Gene that I get from my mother, and the variant of this Gene that I get from my father.
We all have two copies in our regular somatic cells and our body cells. We have except for-- If we think about the, xx and the xy chromosomes, the sex determining chromosomes, on all the other chromosomes we have two copies of the same Genes.Chromosomes, DNA, Genes, and Alleles
We just have two-- It's just they're different variants. One variant from your mother and one variant from your father, or you could say that they are different Alleles.