<span>Norepinephrine uses the Second
Messenger System, which means, cells signal to each other what molecules have
been released that will trigger a physiological reaction. </span>
<span>
This phenomenon is activated after the ligand (ion or molecule) is bonded to its receptor
(protein molecule), creating a variation that causes a chain-reaction, that will
finally activate the Second Messenger. The latter will activate intercellular
molecules that will be able to control the cell’s activity. </span>
Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
Answer:
The amount of mass that planet Jupiter has in the solar system makes it approximately five times larger than all other planets in it. As Jupiter’s gravity pulled on another planet tightly, its diameter grew and it expanded. The density and gravity continued to increase, resulting in even more planet compression.
Explanation:
Answer:
they developed some structures or parts to survive
the terrestrial environment
b. the burning of fossil fuels for energy and transportation
