In the absence of lactose, the repressor protein encoded by the I gene binds to the lac operator and prevents transcription. Binding of allolactose to the repressor causes it to leave the operator. This enables RNA polymerase to transcribe the three genes of the operon.
A tough-skinned tropical fruit, the mango features a sweet, orange- to red-color flesh inside when ripe. Kensington pride, Kent, Palmer and sensation are only a few of the many varieties of mango available through groceries and markets.
Indian mango is extremely sweet and this whole fruit turned black within 24 hours. Mango ripens well in a dark place at the proper temperature and humidity. You can leave it in the special packing material it is packed in, but place it in a warm place. Some people place it in a brown bag with bananas.