Chapter 4 Chapter 4 9

That stringy thing in a test tube is the DNA. But in the naked eye, it’s impossible to tell where it came from. That is due to the reason that DNA looks totally the same in almost every organism on earth. Living things whether it is animals or humans have unique DNA. It doesn’t matter where it came from, it has the same molecule.

This is the order of letters in code making every organism different.

It’s Our Body’s Composition

The order of the building blocks in strand of DNA is what making up the “sequence”.

We are capable of reading DNA sequence such as letters in book. The truth is, we are all aware of the sequence of entire human genome – that’s 3 billion letters, which is enough info to fill in books with 1000 to 2000 pages.

Contained in this 3-billion letters of human genome are around 21000 genes. Majority of the known code are for protein but some of the codes are intended for the RNA molecules.

Almost the Same yet Not

As mentioned, humans have the same arrangement of genes. More than 99.9 percent of sequence of DNA is the same. However, the few differences between are more than enough to make every one of us unique. On average, human genes have 1 to 3 bases that are different from one person to the other. Such differences change the function and shape of protein or they could change how much protein is made, where it is made or when it is made.