Answer:
The estimates I've read are similar to yours: 200 to 400 billion stars. Counting the stars in the galaxy is inherently difficult because, well, we can't see all of them.
Explanation:
Gravity is making him fall to the ground
Answer:
two jaguars per thousand hectares
Explanation:
Population density is the measure of the number of organisms per unit area or volume. This value is especially important when trying to determine the capacity of a certain area to support a given species of plants or animals as well as the effect of such organisms on the ecosystem.
Answer:
Nonhuman life in an urban ecosystem differs from that in an undeveloped forest ecosystem
Explanation:
Answer;
-Pumps require energy for transport because they move material against an electrochemical gradient, but channels and carriers do not use energy because they only facilitate diffusion down a molecule's or ion's electrochemical gradient.
Explanation;
-Permeability is conferred by two classes of membrane proteins, pumps and channels. Pumps use a source of free energy such as ATP or light to drive the thermodynamically uphill transport of ions or molecules. Pump action is an example of active transport.
-Channels, in contrast, enable ions to flow rapidly through membranes in a downhill direction. Channel action illustrates passive transport, or facilitated diffusion.