Viral Structure and Replication Concepts

The video tutorial explores the nature of viruses, questioning if they are alive by examining their characteristics. It delves into the structure of viruses, including components like the capsid and nucleocapsid, and describes various virus types such as helical, polyhedral, enveloped, and complex viruses. The tutorial also covers the sizes of viruses and provides examples. Finally, it explains viral replication through the lytic and lysogenic cycles, detailing how viruses hijack host cells to reproduce.

Which of the following is NOT a characteristic of living things?

• Made of cells

• Contain DNA or RNA

• Reproduce independently

• Respond to environmental stimuli

What is the function of the capsid in a virus?

• To provide energy for the virus

• To enclose the viral genome

• To replicate the virus

• To attach to host cells

Which type of virus has a rod-shaped structure?

• Complex virus

• Polyhedral virus

• Helical virus

• Enveloped virus

What is the approximate size of a human blood cell compared to viruses?

• 1,000 nanometers

• 100 nanometers

• 100,000 nanometers

• 10,000 nanometers

In the lytic cycle, what is the first step of viral replication?

• Genome replication

• Attachment to the host cell

• Assembly of new virions

• Release of virions

During the lysogenic cycle, what happens to the viral DNA?

• It integrates into the host DNA

• It forms a new virus

• It is immediately replicated

• It is destroyed by the host cell

How do bacteriophages inject their DNA into host cells?

• By squatting and injecting

• By budding off the host cell

• By fusing with the host membrane

• Through endocytosis

What is the role of the viral envelope in some viruses?

• To help the virus attach to host cells

• To assist in viral replication

• To protect the viral genome

• To provide energy for the virus

Which of the following is a method of viral release that does not destroy the host cell?

• Lysis

• Exocytosis

• Endocytosis

• Fusion

What must happen for a virus to begin the replication process inside a host cell?

• The virus must be destroyed

• The viral genome must be released

• The host cell must die

• The virus must become dormant