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 mango is a very attractive, evergreen tree with glossy, dense foliage. The new shoots are reddish, the mature leaves a dark green. Depending on the variety mango trees can grow huge (to 35 m and 15 m across for seedling trees of older varieties). But you can keep a mango tree small by pruning it regularly.