yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Mutations | Inheritance and variation | Middle school biology | Khan Academy


2m read
·Nov 10, 2024

  • [Instructor] In this video, we're gonna talk a little bit about mutations, and I wanna apologize ahead of time. My voice is a little strange today. I rode more roller coasters than I thought I would yesterday, and I screamed a little bit.

But anyway, (chuckles) what we see right over here is what's often known as the central dogma of biology. It explains how we go from information in our DNA, which is really sequences of nucleotides. Genes are segments of our DNA that code for specific things.

So we see these nucleotides, which we denote with A, C, Gs, and Ts. And every three of them, that's known as a codon, and for every three of them, it's associated with an amino acid. In other future parts of your biology education, you'll go into more depth on the molecular structures of amino acids.

But what you need to know now is the amino acids are essentially strung together. And then they create proteins. And proteins have all sorts of functions in your body. To a large degree, they make you, you. They construct what you are.

So this is a simplified version of how we go from DNA to you, to some degree. Now, mutations, as you might know, even when you watch some movies, these are changes in DNA. You might have seen superheroes be exposed to radiation or some type of chemical, and then they get mutations, and then all of a sudden they have powers.

Well, we don't know about too many mutations that create the ability to fly or to stick to walls. But mutations are a way that we get new genetic information in the gene pool. Now you might be saying, wait, I already know about sexual reproduction. Sexual reproduction creates variation. And that's true.

Sexual reproduction creates variation, but it really just shuffles around the genes and the chromosomes they're on that exist already inside of a gene pool. Mutations are actually changes in the genes. Now, where do these mutations come from?

Well, there are sometimes errors when DNA is copied, but it can also happen from environmental influences, like radiation or other things. Now, as you can imagine, many times, if you were to just all of a sudden eliminate some nucleotides, or if you were to change them into something else, that might be harmful.

All of a sudden it might code for an amino acid here that does not allow this protein to function properly. Sometimes, it can be beneficial. And that's how we can get new versions of genes, alleles, or new genes altogether.

All of a sudden this became that, this becomes a different amino acid, maybe this protein functions better. And then as you can imagine, sometimes, it doesn't matter at all. Maybe the different amino acid here really doesn't change the structure of this protein.

And in some cases, you can even change a nucleotide and it still codes for the same amino acid.

More Articles

View All
The Current State of the Stock Market (2021)
So that right there is Charlie Monkey. He’s essentially Warren Buffett’s right hand man. He is the vice chairman of Berkshire Hathaway. What we’re looking at right here is him giving a talk at the Daily Journal shareholders meeting, which happened a coupl…
Consumer credit unit overview | Teacher Resources | Financial Literacy | Khan Academy
Hi teachers, Welcome to the unit on consumer credit. So, just as a high level, this is going to cover everything from credit scores—what is it? How it’s able to give people who might give someone credit a sense of how likely you are to pay back that cred…
Proving the SSS triangle congruence criterion using transformations | Geometry | Khan Academy
What we’re going to do in this video is see that if we have two different triangles where the corresponding sides have the same measure. So this orange side has the same length as this orange side. This blue side has the same length as this blue side. Thi…
Everything We Don't Know
This is green. This is red. And this is blue. But how can you tell that what you’re seeing as blue is the exact same thing as what I see as blue? We’ve named the colors to give us a way to communicate and reference them, but in reality, there’s no way of …
Area of quadrilateral with 2 parallel sides
What we’re going to try to do in this video is find the area of this figure. We can see it’s a quadrilateral; it has one, two, three, four sides. We know that this side and this side, that they’re parallel to each other. You can see that they both form ri…
Karn Saroya on the Capital-Light Way to Start an Insurance Business
All right, and so today we have Karnes Roya, the CEO of Cover, which was in the Winter 2016 batch of YC. So, Karnes, what does Cover do for us? “All, thanks for hosting me! I appreciate it. So, you can think of Cover as a multi-line national property ins…