The lac repressor protein is bound to the operator region of the lac operon when there is no lactose in the medium. When introduced in lactose, it binds to an allosteric site on the repressor causing its to change conformation and release from the operator. This allows the polymerase that is bound to the promoter region to proceed transcription of the lac operon genes (LacZ, Lac A, and Lac Y). Translation of these genes forms enzymes that enable the organism to break down lactose for energy.
Answer:
Big Joe is the main character or the protagonist
Explanation:
Answer: Immune system
Explanation:
Lymphocytes are a class of white blood cells (leukocytes) involved in immune response when activated by the a foreign molecule (an antigen). B lymphocytes develop in the bone marrow of mammals and are responsible for the production of circulating antibodies.
Thus, lymphocytes are associated with the immune system.