How does a viral particle enter an animal host cell?

Answer 1

The virus sticks to the cell it is going to attack, injects its DNA and other life functioning items from it, the cell is tricked into making copy's of the items, the parts assemble into more viruses, and finally the viruses break out of the attacked cell and the cell bursts.

Answer 2

A virus has proteins (called protein markers) on its coating (capsid), which allows the virus to attach itself to the host cell. It then injects its nucleic acid (DNA/RNA) into the host to replace the host's genetic material. This is a step in the lytic cycle, see the related question below for more details of this entire viral replication process.

More:

Enveloped and non-enveloped viruses enter a host cell in two ways. The capsid or viral envelope can fuse with the host cell membrane and release the viral material into the host cell, or the virus can trick the host cell. In endocytosis, the virus tricks the host cell by attaching to surface molecules, usually receptors that bind molecules essential to the cell's function, and are then passively carried into the cell. With both methods, the virus is able to penetrate the cell's membrane and enter the cell.

See also the related questions below for more information on how viruses use a host to replicate, including the Lytic steps and the merges with host cells.

Answer 3

Generally, the cell will lyse (burst), releasing the newly formed viral particles. Most DNA viruses and non-enveloped RNA viruses use this mechanism.

However, sometimes the virus can exit the cell without killing it (by budding off from the plasma membrane), so the cell continues to produce even more virus. Some enveloped RNA viruses and retroviruses do this.

Cell lysis is the most important mechanism of viral release.