甚麼是ＤＮＡ,它在遺傳上的作用?

DNA is 脫氧核糖核酸 it is made up of ACTG(Adenine,Cytosine,Thymine,Guanine)
In bacteria, there are rings of DNA(plasmid) that ca be sent to other bacteria (Transformation) if we can cut a strip of DNA with enzymes, we can put it into plasmids and put it in the bacteria by transformation and modify the genes of it.
By this method we can make bacteria that can produce drugs like insulin or study the functions of sections of genes.