Ask Science unravels the confusion between genes, DNA, chromosomes, genetics, and other technical terms that are thrown around in science news.
We talk a lot about genes, but sometimes it can get a little confusing distinguishing between genes, DNA, chromosomes, genetics, and other technical terms that are thrown around in science news. So today let’s take some time to unravel the confusion.
Once Upon a Time...
Once upon a time, deep inside your cell, was a little molecule called adenine. Some people pronounced his name like add-eh-nin, while other people called him add-eh-neen.
But his closest friends just called him Addy.
Addy was pretty happy with his job. He was a nucleotide, one of 4 different types (and in his opinion, he was the best type). The other types of nucleotides were cytosine, guanine, and thymine, but Addy’s mother had always insisted he grow up to be an adenine, like his father.
As a nucleotide, Addy’s main job was to bond with other nucleotides to form DNA, or deoxyribose nucleic acid, the most important molecule in the universe (he admitted that this was a rather subjective opinion, but probably true nonetheless).
One of the things that Addy liked most about being a part of DNA was how orderly it all was. Early in his life, Addy had been assigned to his chromosome, a massive DNA molecule nestled snugly inside the nucleus of a human cell. Addy always felt that he’d been fortunate to have been assigned to chromosome 17, a close knit group of about 78 million nucleotides.
Of course, just like most of the other chromosomes, there were two copies of chromosome 17: one from the organism’s mother and one from its father, but Addy privately thought he was on the better copy.
Some of Addy’s neighbors felt like chromosome 17 was a bit overcrowded; but whenever Addy heard them complaining about the tight space, he’d just remind his friends how lucky they were not to be stuck somewhere like chromosome 1, which had over 247 million nucleotides, three times as many as they had in chromosome 17.
Still, some of them would lament that they hadn’t been lucky enough to be on one of the other 23 pairs of chromosomes. “Look at chromosome 21,” they’d whine. “Only 46 million nucleotides. So much room to spread out!”