Minute to Understanding: DNA 101


DNA 101 — Building blocks of the genome

The Jackson Laboratory's "genetic engineer" takes you from base to genome to learn about DNA. That's the ticket!

DNA? Genes? Genomes? What? Don't worry. If you're confused, just board the DNA to genome express train.

Picture a train track. Each railroad tie represents the smallest building block of DNA, a base pair. There are two types of base pairs, A and T, and G and C, and they're shuffled all along the track in a unique sequence. String all these bases together and you have DNA.

Now, picture a train car. The car spans a certain number of railroad ties, a unique DNA based sequence. That is a gene. A gene controls a certain characteristic, like green eyes. Here comes the rest of the train, each car a different gene, and each controlling a different characteristic.

Now picture the entire train route. All along this route are many trains. This is what a chromosome looks like. Humans have 23 chromosomes, 23 train routes say. From all the way up here we can see all 23 routes at once. This is a genome.

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