"mutations in the laci and laco genes in the lactose system often lead to full production of the three structural genes related to the lac operon even with no lactose available to the organism. such mutations would be called "

constitutive mutations

Explanation:

Constitutive mutations -

They are the strains which uninterruptedly make proteins , and therefore , can lead to excess of protiens and the process is very difficult or nearly impossible to stop , is known as the process of Constitutive mutations .

One of the example of this process of Constitutive mutations is ,

The strain with lac operon mutation which can even results in th etranscription of the lac genes .

Hence , from the statement of the question ,the correct term is Constitutive mutations .  

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