Originally Answered: 7th grade science homework help?
1. Viruses are not cells and do not have a cell membrane or other components of living cells. They cannot reproduce on their own. They cannot move on their own. They also can not use energy. They are alive in the sense that they are organic material, but not in the sense that they are independent living things.
Also they cannot respond to stimulus.
2.Basic structure= Capsid (outer shells that house the nucleic acid), nucleic acid (the genetic material), neck, tail sheath, some internal proteins, tail fibers, end plate, and pins.
3. a virus injects its DNA into the host cell making it produce multiple copies of that DNA and multiple copies of the protein capsule of that virus. After a while, the host cell becomes full of many copies of that virus, then the host cell explodes releasing all the new viruses.
This phenomena is done in two ways either by lytic cycle in which virus DNA survive and bacterial cell destroy, the second is lysogenic cycle in which virus multiply with host cell DNA.
hope that helps , i googled it , saved you time :)