molecular help 22 What is the process of the loss of repress

molecular help

22. What is the process of the loss of repression called in the lac operon? 23. What is the phenotype of lacl/lacl- with respect to lacz expression? Use one word to answer this question. 24. Is the lacl allele dominant or recessive or neither or both (choose one)? 25. Which gene among the lac operon mutant genes we studied is cis-dominant? 26. What is the functional (active) activator molecule in catabolite repression?

Solution

22. The process of loss of repression in lac operon is called negative regulation. Positive regulation in the lac operon is through the catabolise repression or the CAP protein.

23. Lac repressor/ Constitutive gene

24. It is recessive . LacI⁺ is dominant to lacI^-

25. LacI gene.

26. Activator protein is the cAMP receptor protein or CRP also known as the CAP protein.