The smallest blood vessels, known as are where oxygen transfer takes place with cells in the body.

They are called Capillaries.. hope this helps and if you can please rate me AwA

Birth orgraduate orschool

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.