Facts About Your DNA Inside every cell in your body there is a nucleus that contains your genetic material. That genetic material is deoxyribonucleic acid – DNA for short. Your DNA controls many of the things about you, but scientists still are not sure about the exact role of nature (your genes) and nurture (how you were raised) in making you who and what you are. Here are some facts: • Almost every cell in your body contains about 2.91 billion DNA. • The DNA is divided into two sets of 23 chromosomes. • You get one set of chromosomes from your mother and one set from your father. • Every time your cells divide, the information is copied and divided into the new cells. Every time those chromosomes are passed on from mother or father, they are recombined to make unique chromosomes — YOUR chromosomes. Nucleotides and the Structure of DNA • Structurally, DNA is made up of nucleotides. • A nucleotide is made up of a sugar, a phosphate and a base. • Each nitrogenous base pair is held together by weak hydrogen bonds and stacked flat on top of each other like steps. • To each base pair, a two sugar-one phosphate complex is attached. This formed the so-called nucleic acid. • Nucleotides hook together to make the sugar-phosphate backbone of every strand of DNA. • The bases pair up with opposite matching bases on the other strand of DNA that makes up the “double-helix” structure. • The pairs are linked by weak hydrogen bonds. • There are four kinds of nucleotides or “base pairs” -- A for adenine, T is for thyamine, G is for guanine and C is for cytosine. A always pairs with T. G always pairs with C. • They are linked together (the two strands of DNA) and stacked like a ladder who’s sides spiral around each other into their famous double helix shape. The Structure of DNA 1. Structurally, DNA is made up of nucleotides. 2. A nucleotide is made up of a sugar, a phosphate and a base. 3. Nucleotides hook together to make the sugar-phosphate backbone of every strand of DNA. 4. Bases pair up with opposite, matching bases on the other strand of DNA. 5. There are four kinds of base pairs made up of adenine (A), thyamine (T), guanine (G), cytosine (C). A always pairs with T. G always pairs with C. 6. The two strands of DNA are linked together by weak hydrogen bonds and stacked like a ladder who’s sides spiral around each other into their famous double-helix shape. Nucleotide sugar+phosphate+base phosphate sugar base sugar-phosphate backbo ne phosphate sugar c g a c c g c t t g a c t double-helix shape of DNA cytosine guanine weak hydrogen bonds cytosine base pairs adenine thymine guanine