The Lifecycle of a Virus

The video tutorial explains the nature of viruses, highlighting that they are not true organisms as they cannot replicate independently. It describes the basic structure of viruses, including genetic material and a protein coat called a capsid. The tutorial covers how viruses replicate by infecting host cells, detailing the lytic and lysogenic cycles. In the lytic cycle, viruses inject genetic material into a host cell, leading to the production of new viruses and cell lysis. The lysogenic cycle involves the integration of viral genetic material into the host's chromosome, allowing replication with the host cell. The video concludes with a summary of these cycles.

What distinguishes viruses from true organisms like animal and plant cells?

• They have a nucleus.

• They consist of genetic material inside a protein coat.

• They can replicate independently.

• They have a cell wall.

What is the role of the capsid in a virus?

• It stores nutrients.

• It produces energy.

• It helps the virus move.

• It protects the genetic material.

Why do viruses need a host cell for replication?

• To increase their size.

• To hide from the immune system.

• To replicate their genetic material and produce viral proteins.

• To obtain nutrients.

In the lytic cycle, what happens to the host cell after viral replication?

• It repairs itself.

• It bursts open, releasing new viruses.

• It divides into two cells.

• It becomes dormant.

During the lysogenic cycle, what happens to the viral genetic material?

• It remains outside the host cell.

• It forms a new virus immediately.

• It integrates into the host's chromosome.

• It is destroyed by the host cell.

How does the lysogenic cycle differ from the lytic cycle?

• The lysogenic cycle involves immediate destruction of the host cell.

• The lysogenic cycle integrates viral DNA into the host's genome.

• The lysogenic cycle produces viruses without a host cell.

• The lysogenic cycle occurs only in plant cells.

What can trigger the switch from the lysogenic cycle to the lytic cycle?

• The host cell's division.

• Separation of viral genetic material from the host chromosome.

• A change in temperature.

• The presence of antibiotics.