Primary Meanings of fold. 1  v bend or lay so that one part covers the other. 2  v become folded or folded up. 3  n the act of folding.  n an angular or rounded shape made by 1  folding. n a folded part (as in skin or muscle)  n a geological process that causes a bend in a stratum of 1  rock. n a pen for 2  sheep. n a group of sheep or  goats.
Each gene has a special job to do. The DNA in a gene spells out specific instructionsâmuch like in a cookbook recipe â for making proteins (say: PRO-teens) in the cell. Proteins are the building blocks for everything in your body. Bones and teeth, hair and earlobes, muscles and blood, are all made up of proteins.
Nucleus is the part that contains the DNA. Inside the nucleus, DNA may be coiled in a form of chromosomes.