Action potentials (i.e. nerve impulses) occur in several types of animal cells<span>, called </span>excitable cells<span>, which include </span>neurons<span>, </span>muscle cells<span>, </span>endocrine<span> cells, and in some </span>plant cells<span>. </span><span>It takes around 40 action potentials for a smell sensation to be reported.</span>
All the members of a specific species that live in an area are a population.
All three are bad for the environment because all three types release CO2 into the air and have throughout their constant usage helped with creating the greenhouse effect that traps heat and causes global warming. That's why clean energy is a necessity and people are developing harnessing wind and solar power.
6. Lion
7.raccoon
8.rat
9. A keystone is a organism that helps define the entire ecosystem, and if the species were to disappear from the ecosystem no other species would be able to fill its ecological niche the ecosystem would be forced to radically change allowing new and possibly invasive species to populate the habitat.
