Which of the following illustrates a complex virus?

• A. Poliovirus
• B. Influenza virus
• C. Bacteriophage T4
• D. Hepatitis B virus

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what defines a complex virus. Complex viruses have more intricate structures than simple helical or icosahedral viruses, often including additional components such as tails, complex protein coats, or multiple layers.
2. Step 2: Review the structural characteristics of each virus option: Poliovirus is a simple icosahedral virus, Influenza virus is an enveloped virus with a segmented RNA genome, Hepatitis B virus is an enveloped DNA virus with a partially double-stranded genome, and Bacteriophage T4 is known for its complex structure including a head, tail, and tail fibers.
3. Step 3: Identify which virus has the hallmark features of a complex virus. Bacteriophage T4 has a distinct head-tail morphology with a contractile tail and base plate, which is characteristic of complex viruses.
4. Step 4: Compare the other viruses to confirm they do not have complex structures. Poliovirus, Influenza virus, and Hepatitis B virus lack the elaborate tail structures and additional components seen in complex viruses.
5. Step 5: Conclude that Bacteriophage T4 is the correct example of a complex virus based on its unique structural features.