Which best scientists determine the age of fossils

Relative dating best helps determine fossil age. It's where layers of sedimentary rock and fossils pile up on top of each other; the oldest fossils being in the bottom layer and the youngest in the top.

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.