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>
Answer:
Skin acts a defensive and protective layer. It protects the internal body from pathogens, which are disease causing bacteria. The skin can fend off bacteria, particles, foreign bodies, etc.
Explanation:
1. The virus attaches itself to a host cell
2. The virus inserts its nucleic acid into the host cell
3. The virus nucleic takes over the host cell and makes virus parts
4. The cell creates more viruses
5. The cell bursts, releasing the new viruses