LOCAL ENVIRONMENT ISSUE:
People dump a lot of trash in the sea, and the sea creatures living there goes through a lot of trouble to live with all the muck getting in them. Of course, don't write it like that in your assignment - you'll get told off for the straight forwardness.
Answer
Operons are cluster of coordinated genes, including structural genes, an operator gene, and a regulatory gene.
Explanation:
In the The repressible operons, The transcription is usually on and repressor is in inactive form, So the specific genes are transcribed. While a regulatory molecule act as corepressor and binds to repressor protein to activate it. The repressor protein cause the inactivation of repressible operon (as the name indicate). E.g., Tryptophan Repress the trp operon.
A high level of product act as regulatory molecule (Corepressor) and turn off the operon, So anabolic pathways or synthesis of essential components are controlled by repressible operon.
In the Inducible operons, the transcription is usually off and repressor is in active form. So there is no transcription of genes. Specific Metabolite cause the activation of operon e.g lactose cause the induction of lac operon.
As a metabolite induces the operon, So they control the Metabolic pathways or breakdown of a neutrient.
<span>Thinking of the layers of the earths crust, it would be expected that the mantle is rich in minerals that contain heavy metals such as iron and nickel.</span>
Since the air is a great thermal isolator, the windows prevent heat exchange better than one made out of a single thick sheet of glass. The air between the thin blankets is not moving around and will form an isolating layer that acts exactly like another blanket, thus improving the thermal isolation
