Because with that the mitochondria will make ATP (energy) for the cell and your body
I just learned that today XD
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
Answer:
The three basic items to make an electromagnet are a source of current, conducting wire, and a metallic core. Electromagnetic is a type of magnet which is formed with the help of electricity.
When the current is allowed to pass through the wire and the metallic core, the magnetic field is generated around the metallic core and when the current is turned off, the metallic core losses the property of magnetism.