o Biochemic mechanism 1)Interfere nucleotide synthesis. 2)Impact the structure and function of DNA 3)Interfere transcription and block rNa synthesis 4) Interfere protein synthesis and functions 5) Change hormone lever.• Biochemic mechanism: • 1) Interfere nucleotide synthesis. • 2) Impact the structure and function of DNA • 3) Interfere transcription and block RNA synthesis. • 4) Interfere protein synthesis and functions. • 5) Change hormone lever