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.
The allure is foremost about the taste but also about anticipation and uncertainty: Mango season in the region lasts only about 100 days, traditionally from late March through June; is vulnerable to weather; and usually brings some sort of mango crisis, real or imagined.