What is the difference between DNA, gene and chromosome?

The main difference is one of size. The smallest of all is the gene. From then on, the thing increases: several genes in sequence form the DNA, a set of molecules that carries the genetic information of all living beings. “A comparison helps to understand this difference. If we imagine that DNA is a necklace, each of the beads that make up the necklace will be a gene”, says geneticist Mayana Zatz, from the University of São Paulo (USP). It turns out that DNA is a huge “necklace”: if the DNA present in a single human cell could be stretched out in a straight line, it would reach 2 meters in length. How to make this whole thing fit in each of our microscopic cells? That’s where chromosomes come in. They are structures present in each of the 100 trillion cells of the organism that serve precisely to store the DNA. Inside the chromosomes, the huge strand is supercondensed, coiled like a spring in a tiny space. Apart from this difference in size, the rest is just similarity, since DNA, gene and chromosome basically serve the same thing: to determine and pass on the characteristics that shape the way of each living species. It is this set of genetic information that will indicate from the species to which the living being belongs (whether it will be a man, a camel or a fish) to more individual traits, such as eye color, blood type and the shape of the toes. . The most impressive thing is that a small change in this genetic material is enough to completely alter a living being. It is worth remembering a well-known example: man and chimpanzee share 98% of their DNA. It’s only the remaining 2% that determines the world of difference between us and our furry relatives.