EVERYDAY SCIENCE

Detailed explanation-1: -The first stage is entry. Entry involves attachment, in which a virus particle encounters the host cell and attaches to the cell surface, penetration, in which a virus particle reaches the cytoplasm, and uncoating, in which the virus sheds its capsid.

Detailed explanation-2: -Step 1: Attachment: The virus attaches itself to the target cell. Step 2: Penetration: The virus is brought into the target cell. Step 3: Uncoating and Replication: The enveloped virus loses its envelope, and viral RNA is released into the nucleus, where it is replicated. Step 4: Assembly: Viral proteins are assembled.

Detailed explanation-3: -The critical first step in the virus replication cycle is the attachment of the virus particle to a host cell.

Detailed explanation-4: -Viruses initially stick to cell membranes through interactions unrelated to fusion proteins. The virus surfs along the fluid surface of the cell and eventually the viral fusion proteins bind to receptor molecules on the cell membrane (4). If only binding occurred, the two membranes would remain distinct.

Detailed explanation-5: -Replication: The virus takes over the cell’s metabolism, causing the creation of new proteins and nucleic acids by the host cell’s organelles. Assembly: Proteins and nucleic acids are assembled into new viruses. Release: Virus enzymes cause the cell to burst and viruses are released from the host cell.