Lac (lactose) operon in a type of bacterial operon, which shows a cluster of genes that are regulated by a single promoter. It is composed of an operator, promoter, a terminator, and three structural genes (lacA, lacY, and lacZ), which are responsible for the transport and breakdown of lactose.
The lac operon is an inducible operon as it gets activated in the presence of lactose and expressed its functional genes in the form of proteins (or enzymes) for lactose metabolism.
Thus, the correct answer to be fill in first blank is 'inducible' and in second blank is 'lactose.'
The lac operon in E.coli regulates genes that code for enzymes required for breakdown of lactose. The lac operon is <span>an inducible operon </span>that is activated in the presence of lactose.
In this image the bird is eating an insect off of a leaf that is easy to see whereas the insect on the other leaf is camouflaged and still alive. This helps illustrate the concept of natural selection because the camouflage insect is able to survive longer and therefore reproduce more.