Tag: DNA

What is DNA? – A Word On Science

by Svara Jayasinghe

Have you ever wondered what DNA is? I was watching an episode of NOVA Wonders called “Can We Make Life?” that got me thinking about DNA. Deoxyribonucleic acid, or DNA, is a molecule that contains our genetic code. The genetic code is what makes living things have certain characteristics. For an example, my skin is brown because my genetic code has instructions to make a chemical called Melanin that makes my skin brown. DNA exists in every living thing. In humans, DNA is located in the nucleus. The structure of DNA is called a double-helix that has two DNA strands that are twisted around each other. You can think of this like a twisted ladder. Each DNA strand is a row of four different chemicals called Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). These chemicals are called nucleotides. The nucleotide “A” pairs with “T” and “C” pairs with “G”. This pattern is always the same, and does not vary. DNA is inherited by children from their parents. This is why children share traits or features, like hair color, eye color, and skin color, with their parents.

If you want to know more about DNA, you should watch the episode of NOVA Wonders: “Can We Make Life?” at:

https://www.pbs.org/video/nova-wonders-can-we-make-life-dzcxg8/

The Human Genome Project

By Simran Jayasinghe

We have all heard of DNA. DNA stands for deoxyribonucleic acid. You are probably wondering, why you need DNA? DNA is basically the instructions for every single cell in your body.  DNA makes a shape like a spiral staircase that is called the double helix. In most organisms, DNA is found in the nucleus of every cell. DNA is made up of four chemicals called nucleic acids: adenine (A), thymine (T), cytosine (C), and guanine (G). A always pairs with T, C always pairs with G. The complete set of your DNA is called your genome.

human genome projectThe Human Genome has about 30,000 genes in it. A gene is the part of the DNA that determines  an organism’s features. Genes can determine the color of your eyes, the color of your hair,    the color of your skin, how tall you will be, and things like that. When there is a mistake in a gene, it can sometimes cause diseases like Parkinson’s disease, Cystic fibrosis, and Spinal Muscular Atrophy. It would help doctors if they could look at the genes of a patient, because they might find out if that person will have a certain disease. They can find out a patient’s genes by looking at the patient’s genome.

The Human Genome Project was a effort to sequence all the genes that are found in us. The Human Genome Project took 13 years to complete, and cost 3 billion dollars. The Human Genome Project was finished in 2001. Today scientists can sequence one genome overnight!. Since we can sequence human genes very quickly doctors can determine which patients will get a genetic disease. This ability has also led to a field called Personalized Medicine.  To read more about personalized medicine see my sister Kiran’s entry.