Answer:
We live in an era of unprecedented road and highway expansion — an era in which many of the world’s last tropical wildernesses, from the Amazon to Borneo to the Congo Basin, have been penetrated by roads. This surge in road building is being driven not only by national plans for infrastructure expansion, but by industrial timber, oil, gas, and mineral projects in the tropics.
Few areas are unaffected. Brazil is currently building 7,500 kilometers of new paved highways that crisscross the Amazon basin. Three major new highways are cutting across the towering Andes mountains, providing a direct link for timber and agricultural exports from the Amazon to resource-hungry Pacific Rim nations, such as China. And in the Congo basin, a recent satellite study found a burgeoning network of more than 50,000 kilometers of new logging roads. These are but a small sample of the vast number of new tropical roads, which inevitably open up previously intact tropical forests to a host of extractive and economic activities.
Explanation:
joints form our musculoskeletal system which lets muscles move
Cyclins
are the chemicals that regulate the cell cycle. Cyclins work by regulating the timing
of the cell cycle in eukaryotic cell. Cyclins activates cyclin dependent
kinases (CDKs) (an enzyme that works by adding <span>negatively charged phosphate groups to other
molecules in a process called phosphorylation) by binding to it to form a cyclin-Cdk
complex. This complex then functions by acting as a signal to the cell to move
to the next cell cycle phase. At the end of the event, the cyclin is degraded, Cdk
is deactivated, therefore signaling exit from a specific phase.</span>
It prepares to fight danger or run from it. It identifies the primary source of danger.
