AP BIOLOGY

Detailed explanation-1: -A virus is a tiny, infectious particle that can reproduce only by infecting a host cell. Viruses “commandeer” the host cell and use its resources to make more viruses, basically reprogramming it to become a virus factory. Because they can’t reproduce by themselves (without a host), viruses are not considered living.

Detailed explanation-2: -Viral entry is the earliest stage of infection in the viral life cycle, as the virus comes into contact with the host cell and introduces viral material into the cell.

Detailed explanation-3: -Once a virus gets into a host’s body, it travels along the surfaces of cells until its proteins begin to bind with receptors on the cells. The virus and the cells then fuse, allowing the DNA or RNA inside the virus to enter the cells, where it begins to reproduce.

Detailed explanation-4: -Viruses are microscopic biological agents that invade living hosts and infect their bodies by reproducing within their cell tissue. Viruses are tiny infectious agents that rely on living cells to multiply. They may use an animal, plant, or bacteria host to survive and reproduce.

Detailed explanation-5: -They do not possess ribosomes and cannot independently form proteins from molecules of messenger RNA. Because of these limitations, viruses can replicate only within a living host cell.