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.
When ripe, mangos feel soft when given a gentle squeeze and when a sweet, fragrant scent emanates from the stem-end of the fruit. If your mango is rock hard when you squeeze it (and donât press too hard, or youâll risk damaging the fruit), it means it is not ripe yet. Just let it sit at room temperature until it ripens (softens).