What is a Gene?
Genes are basic units of information within cells.
Genes tell cells how to make all the many different proteins they need to grow, survive and function. Genes are made of DNA.
If you’d like to get a sense of DNA’s shape and size - in the grand scheme of things - try this classic and fun video: https://www.youtube.com/watch?v=0fKBhvDjuy0 (DNA appears in the second half).
Every cell in your body contains copies of the same DNA molecules. Your DNA molecules are copied from your parents. That’s a lot of copying. Keep that in mind for later.
DNA is a very long, thin, tightly coiled chain of tiny molecules called bases. There are only four kinds of base, called A, T, C and G. Billions are joined in each chain. Their order makes a code.
Each cell makes its proteins by reading and then decoding (translating) the order of bases in special stretches of DNA. These special stretches are the genes. Each gene encodes a different kind of protein.
It’s important to know that most DNA (98%) is NOT in genes and we don’t know what it does.
It’s also important to know that not all genes are decoded in all cells. Different cells, e.g. liver, heart, brain cells and so on, decode different sets of genes. That’s how they get their specialized functions.