Answer:
they bind to protein-coupled transmembrane receptors with higher complexity than those found in prokaryotes
Explanation:
G-proteins are proteins found inside the cells that function as molecular switches which are activated by binding to guanosine triphosphate (GTP), while they are inactive by binding to guanosine diphosphate (GDP). The G-proteins bind to G-protein-coupled transmembrane receptors (GPCRs) in the cytoplasmic region. The GPCRs are a very diverse group of proteins that are activated by extracellular molecules ranging from small peptides to large proteins, including pheromones, neurotransmitters, light-sensitive compounds, etc, thereby allowing them to respond to diverse stimuli from the extracellular environment. In consequence, it is reasonable to suppose that the signaling pathways in which G proteins are involved have a higher complexity level than those observed in primitive prokaryotic organisms.
Answer:
Explanation:
Even if we stopped burning fossil fuels, the Earth would continue warming up for another few decades because of all the heat we've already produced. Global temperatures would climb – finally stabilizing at a level much higher than we've ever known.
The answer is D. In a
geological era, when the plants and animals
in the then environment die, they get buried
in sediments. These sediments are covered
by other sediments of another geological
time within which are the remains of dead species
of the then geological era. These sediments from different geological times have different properties hence
form visible strata that can be studied to identify the kind of environment in the then geological time. Their
fossils can also be studied to identify
the kind of species that roamed the earth during the time.
<span><span>Clouds of gas form within galaxies.
</span><span>Formation of structure within the gas clouds, due to "turbulence" and activity of new stars.
</span><span>Random turbulent processes lead to regions dense enough to collapse under their own weight, in spite of a hostile environment.
</span><span>As blob collapses, a disk forms, with growing "protostar" at the center.
</span><span>At the same time, bipolar outflows from forming star/disk system begin.
</span><span>Material is processed, moving in from the blob to the disk. What is not lost in the outflow builds up on the protostar.
</span><span>When the protostar begins to undergo fusion, it becomes a real star.
</span><span>Once the outflow ceases and the "accretion" phase that lead to the buildup of the star ends, a disk of "leftover" material is left around the star.
</span><span>At or near the end of the star-formation process, the remaining material in the "circumstellar disk" (a.k.a. "protoplanetary disk") forms a variety of planets.
</span><span>Eventually, all that is left behind is a new star, perhaps some planets, and a disk of left-over ground-up solids, visible as a "Debris Disk"around stars other than the Sun, and known as the "Zodaical Dust Disk" around the Sun.</span></span>
