Each nucleotide consists of a nitrogenous base, a sugar (deoxyribose), and a phosphate group. The bonds between nucleotides in the polynucleotide chain are formed by deoxyribose and the phosphoric acid residue. Phosphate groups form covalent phosphodiester bonds between the third and fifth carbon atoms of neighboring deoxyribose molecules.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.