Why do organisms have complex gene regulatory networks?

Gene regulatory networks have an important role in every process of life, including cell differentiation, metabolism, the cell cycle and signal transduction.


Genes, when mutated create different alleles. Remember, a variation in gene sequences creates new alleles.


Tautomerism is the ability of a molecule to exist in more than one chemical form.

Many tautomers are formed by migration of a hydrogen atom, accompanied by a switch of a single bond and neighboring double bond.

In cyclic structures , H- atoms can moved from one atom to another or from ring to another, so they can not assigned a fixed location. This movement is called tautomeric shift.


Cancer often begins as a begiegn tumor. Once it metastases, which could take a while, it becomes malignant, cancerous. This takes time