Basic Genetics Overview: What are Chromosomes, Genes and DNA?

[Music] what is a chromosome a chromosome is part it's a unit of organization of your dna so you know that the dna is essentially the central command in the cell so all major decisions about identity about life and death are encoded in the dna of a cell in every individual cell those three billion coding bases are not simply stretched out and floating all around the cell or even in the nucleus they have a very tight organization they're wound up the dna is wound very tightly into these structures we call chromosomes a chromosome is part of the it's a unit of organization of the dna of the cell that becomes particularly important or visible when the cell divides so when the cell divides the dna condenses into discrete parts that we call chromosomes and because it is very well organized and tightly packaged and because not every chromosome looks like each other we can identify them and we can detect abnormalities in the structural organization of dna that may be linked with diseases a number of diseases clearly cancer is a big part and clearly myeloma is part of the cancers that whose chromosomal makeup is very important what is the structure of a chromosome each chromosome is organized in such a way that we can tell to discrete the short arm and the long half of the chromosome separated by a central part that we call the centromere the short arm is called the p arm usually and the long arm is the qr what is the difference between a gene and a chromosome a gene is part of a chromosome so a chromosome is organized of many genes and also areas of dna in between the genes that do not encode foreign 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 are more functional that would be the cities and then parts in between the cities that are more quiet water genes 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 blonde hair height in the situation of the 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 and if you if cancer cells or when cancer cells lose this ability they become a burden to the community of cells if 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