What is a mutation? Why do mutations occur?

[Music] what is a mutation basically what we think of as mutation is you inherit dna from mom and dad but remember you're starting off as a single cellular organism that divides divides divides into trillions of cells that make up you so we're starting from sperm and egg and getting lots and lots of cells every time a cell divides it has to copy its dna and pass it on to the next cells copy pass it on copy pass it on and every once in a while as it's copying all of those bases of dna it makes mistakes most of those mistakes we never know about but every once in a while a mistake occurs in a gene in which one of those bases one of those coding segments gets altered and if it gets altered in a gene that causes cells to more rapidly divide that's a mutation we want to know about we all carry mutations there is no such thing as totally normal dna we all have mutations we all expose ourselves to sunlight we all expose ourselves to different foods we all make mistakes as our dna is being copied so all of this stuff happens now fortunately there is an incredible proofreading function when we copy dna so that the cells have lots of repair mechanisms to repair mutations but sometimes even those slip through the cracks and what happens is in myeloma individual bases become changed and they never get fixed and if they get changed in a bad gene that causes the cell to proliferate that's an important mutation that can actually cause a tumor to grow what are some things that may cause mutations i always say that people are the dna of every individual and if you if you want to blame your dna who do we blame okay number one we blame mom and dad because most of the dna we got was from mom and dad but then you have to think about blaming yourself because mutations can occur in sunlight sunlight can actually damage dna now most damage that occurs with sunlight damage to dna can cause other types of tumors like melanoma causes the cause of that is uv radiation from the sun so there are examples in your environment of pesticides of foods you eat of toxic agents we are all exposed to things that can alter our dna and some of us do a better job of repairing some of us don't repair nearly as well so mom and dad are to blame things you expose yourself are to blame and then the third one which is the hardest one to explain bad luck i mean imagine you gotta copy those three billion bases over and over and over and over again every once in a while yeah make a mistake and it's nobody's fault it had nothing to do with what you ate it had nothing to do with mom and dad it's just that the system put the wrong piece in there it's a mutation but it's a random error of copying dna