Cc is on so you will see closed captioning. click cc button at bottom right to turn off. Follow us on Twitter (@amoebasisters) and Facebook! What do you think of when you think of the word mutation? Do you think about Xmen and some really awesome ability? Or.the ninja turtles? We loved the ninja turtles when we were little! We might be showing our age a little bit.
But mutations are really not that glamorous. most people understand that a mutation is a change of genetic materialmore specifically a nucleic acid. RNA and DNA are both types of nucleic acids. So how does a change happen? Remember that in DNA, the base adenine (A) goes with thymine (T). And the base Cytosine (C) goes with Guanine (G). And thats all good, but what happens if the wrong base matches up? Many things can cause an error like thatexternal factors like chemicals and radiationor internal things like something goes wrong during DNA replication.
In interphase, which is a stage that prepares cells to divide during mitosis. now while these things can increase the chance that a mutation is going to happen, it is important to understand that mutations are random. If a mutation is going to be a helpful thing for an organismwhich is rare, as very few are helpful it cant just will itself the get that mutation. An organism can’t just will itself to get this. It’s definitely not like Xmen either. More about that in natural selection. Many mutations are actually neutral in their effect.
Meaning they neither help nor harm an organism. And some mutations are harmful. So we’re going to talk about the different kinds of mutations.First we’re going to talk about gene mutations. So DNA makes up genes. And genes code for proteins that influence different traits. So when DNA has changesaka a mutationthen different proteins can be produced and this can affect an organisms traits.
So let’s look at the gene mutations. So first, substitution.That means you have the wrong base matched. So instead of A with T.you can have A with G. Scandalous. You can have an insertion, which means an extra base (or bases) are added in. You can have a deletion, which means a base is removed. Insertions and deletions have the potential to be especially dangerous because remember.
In protein synthesis, we talked about how bases are read in threes? well if you add a base or remove a base, suddenly the number of bases total has changed, right? So if you read in threesdepending on where it happened everything that is read afterwards could get really messed up. We call this a frameshift. Now these were all types of gene mutations, but we also have something called chromosome mutations. Remember that chromosomes are made up of DNA and proteinhighly organizedand they have lots of genes on them. All of the.
Body cells in your body each have 46 chromosomes. Human sperm and egg cells have 23 chromosomes. Well changes can occur at that large chromosome scale too. So let’s talk about these chromosome mutations. Just like insertion in a gene mutationwhere bases can get addedyou have something called duplication in chromosomes. These are mutations where extra copies of genes.
Are generated. so extra copies of that chromosome are generated. There is deletion, where some of the genetic material from the chromosome breaks off. Inversionwhen a broken chromosome segment gets inversed (which means reversed) and put back on the chromosome. Or translocation (we werent kidding back when we said there are a lot of trans words in biology)thats when a fragment from one chromosome breaks off and attaches to another chromosome. Theres more mutations than what we covered.