Not blue jeans though; those are made of denim. The jeans that we're going to be talking about today are spelled G-E-N-E-S. "Genes" are just a weird way of identifying a specific section of a DNA molecule in an organism. Today though, the subject is "genetic mutations," not genes. So what is a genetic mutation?
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| So Trippy |
A genetic mutation happens when a DNA molecule is copied wrong. Most of the time, the change is corrected by DNA repair, but when it isn't the mutations usually are harmful to your body. Examples of harmful mutations, or deleterious mutations, are cancer, which causes uncontrolled cell growth, and sickle-cell anemia, which makes your blood cells be shaped like crescents instead of circles.
Sometimes mutations can be beneficial though. Occasionally people are born without some or all of their wisdom teeth, which is an example of beneficial mutations. Some beneficial mutations can spread across a whole population. That is the basis of evolution.
Mutations can be caused by many different things. Radiation, for example, can break down cells and nucleic acids and cause mutations. Exposure to chemicals can also cause mutations.
Well, that's all for today, hope you liked the post. Bye!
Links:
Blue Jeans Picture
DNA Animated Gif
Sickle Cell Anemia Picture
Radiation Picture
Hey guys, The Scientific Waffle here. and guess what: more nucleic acid???!!! Wow! If you read my last post on deoxyribonucleic acid, you know that DNA is a molecule that contains the blueprints for your body. I also talked about RNA a little bit too, and that's what we're going to talk about to day. Let's get started!
RNA (ribonucleic acid) is a molecule similar to DNA. Well, sort of. The RNA that is most similar to DNA is mRNA, or messenger RNA. mRNA look like DNA with half of it gone. Another difference is that instead of having the chemical bases adenine, thymine, guanine and cytosine, it has the bases adenine, uracil, guanine and thymine. Just like how adenine connects to thymine in DNA, adenine connects to uracil in RNA.
mRNA takes commands from DNA and tells the ribosomes in the cell what to do in the form of the order of the bases on mRNA. For every three bases on the RNA, the ribosome puts one amino acid into a protein. After enough amino acids are combined, a protein is formed. Proteins perform basic functions around the cell.
But ribosomes can't understand the orders given to them by the mRNA. That's where tRNA comes in. tRNA, or translator RNA, translates the orders into something the ribosome can understand. The last type of RNA, ribosomal RNA (rRNA) is inside ribosomes and makes the proteins with the translated orders.
Do all living things have RNA? Yes. RNA is crucial to life. Some scientists believe that in the early times of the earth, life forms didn't have DNA, and the RNA performed the functions of DNA as well as the normal RNA functions.
Well, that's all for today, goodbye!
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I know what you're thinking, what the heck is deoxyribonucleic acid? The thing is, you already know, even if you don't know about yourself knowing what it is =). Because deoxribonucleic acid is actually... DNA! See, you know what it is! But today, I'm going to explain how it works.
Let's get back to the basics. DNA is composed of two spiral columns made of phosphates and sugar. The bars in between the columns are made of four different chemicals called adenine, thymine, guanine, and cytosine. This shape is called a double-helix Each half of a bar is made up of a different chemical. Adenine and thymine are always paired together, while guanine and cytosine are always paired together.
But how does DNA make our body work? Well, that's where RNA (ribonucleic acid) comes in! DNA commands the cell to make RNA, which is threaded through a ribosome, an organelle in the cell. The ribosome then makes proteins according to what the RNA says, and that determines your body traits! Cool, right?
One of the reasons we know about the shape of DNA is because of James Watson and Francis Crick, who made the first correct double-helix model using an x-ray image taken by Rosalind Franklin.
Now for how DNA replicates. The DNA molecule splits down the middle, and new halves on the inner side form. Eventually the DNA splits completely, and there are now two DNA molecules.
Well, that's all for today guys, bye!
Links:
Free BrainPOP Video
DNA Animated Gif
DNA Replication Animated Gif
