What is a gene? What is an allele? What is a genetic trait?

Previous HealthTree University lessons in the Basic Genetics and Tumor Biology course, we discussed about DNA and chromosomes. In this lesson, we'll dive into the fascinating world of genes. You'll discover what genes are made of, where they're located, and how they function. We'll also explore the connection between genes and chromosomes and unravel the mystery of alleles. You'll learn how these tiny units influence genetic traits and get a peek into the exciting field of gene mapping. Let's unlock the secrets of our genetic code.

What is a gene? All of our genetic or our basic information is within our DNA. A gene just refers to a piece or strand of DNA that codes for a specific strain. So, for example, you have a gene that decides what color eyes you will have, a gene that will decide how long is your hair going to be, what kind of hair you're going to have. A gene that decides, you know, like the strength of your nails or the color of your skin. So that is just our genetic, our makeup, that we get, from our parents. And usually, you know, you're half your mom and half your dad. So when we refer to as genes, that's just a one piece of DNA. That's codes for a specific strain itself.

Every cell has a function. If you're a muscle cell, you've got a contract. If you're a brain cell, you've got to think if you're, if you're a pancreatic cell, you got to you got to produce insulin. So every cell has certain sets of functions. And that function of the cell is dictated by the code of DNA. And the unit that that codes for each protein that is giving every cell its characteristics is the gene. And the gene may comprise 50,000 of these base units. I said we have 3 billion of these base units. An individual individual gene may have maybe 10,000, 50,000 or about 100,000 of these units. So it's a small segment of the DNA that codes for the function of the proteins that that cell is making.

In lesson one of this course, the DNA base units that Doctor Van Ness is referring to were explained. These base units are adenine, thymine, cytosine, and guanine. Adenine always pairs with thymine, and cytosine always pairs with guanine, forming the steps of the DNA ladder.

The DNA is laid out in this in an arrangement called a gene, and each gene is the instruction for the body and instruction for the cell to then make some type of protein, which actually does all of the work in the cell. So this could be proteins, like enzymes that help metabolize things that help break down things in the cells. It can be receptors or these things that hang off of the cell that allow cells to interact with one another. Really, anything that cells that the organs in the body need to do. The DNA is has a number of these genes that give the instructions for the cell to design all of the machinery that it has. Genes provide or they encode, as we say, technically, information that, controls some part of the function of the cell. Ultimately, genes or groups of genes control traits such as blue eyes, blond hair, height.

In the situation of the cancer cell. We are particularly concerned about genes that make life or death decisions because essentially cancer cells are cells that have lost the ability to make wise decisions about life and death. So every cell in our body, pretty much every cell, has a normal life cycle. So it's important to know when to divide, when it's time to pass the baton, as it were. And die with cancer cells, or when cancer cells lose this ability. And die with cancer cells, or when cancer cells lose this ability. They become a burden to the community of cells. If they, they reach their normal lifespan and they decide to hang on. That means that you now have more cells than what you should have. And that can set the stage for cancer. Make sure you watch the lessons in this course that explain the function of oncogenes, tumor suppressor genes, and DNA repair genes. And what happens if these genes are mutated?

How does a gene relate to a chromosome? Gene is part of a chromosome. So chromosome is organized of many genes and also areas of DNA in between the genes that do not encode for and or do not contain any genes. So the genes are the part of the chromosome that regulate parts of the function of the cell. And they are organized in such a way that you may have a gene separated by a rather inert territory until you find the next gene. It's more or less like having a city. Then you go on the highway in between two cities and until you find the next city, you have that more sparsely populated area in between two cities. But the whole state would be the chromosome in this case, right? So you have the discrete parts that are more active or functional. That would be the cities and then parts in between the cities that are more quiet.

What is an allele? An allele is the genetic distinction of the two copies you may get of a single protein gene. So if I have a gene that makes insulin I actually have two. I got one for mom and I got one from dad. Each of those genes are considered an allele. And remember, everybody's unique. So it turns out that the sequence of dad's allele maybe a little different than the sequence of mom's allele. And so in fact, you as an individual have two alleles. You have a copy of a gene from dad and a copy of gene from mom. And there are about 99.9% identical, but there may be some slight genetic differences in the two copies. And we refer to those as allelic differences.

What is a genetic trait? A genetic trait is the manifestation of a gene or an allele. It is this specific characteristic that that gene and hence henceforth that allele leads to and the differences that it leads to. So an allele is basically different versions of the gene. So let's say for example that that gene codes for eye color right. So if someone has blue eyes there they will have a different allele versus someone who has green eyes versus someone who has gray eyes just from our black eyes. So the genetic trait that that specific gene and the alleles code for is the genetic trait. And like how it manifests itself based on the variations in the gene and the alleles, the color of your hair, the color of your eyes, everything that you look like is derived from your genes. That's why you kind of look a little bit like mom, if you might look a little bit like dad, because you're getting genes from both of those. So they give you your traits.

The important thing for people to recognize is it's easy to see how genes can vary to give you different traits, because if you sit in a room of a lot of people, everybody looks different. So let's move that one step further. You look different on the inside too. So your cells internally, the genes that they express are just as unique inside you as the traits that you have outside of you.

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