A scientist isolates a disease-causing particle. Which of the following properties would indicate that the particle is a virus and not a bacterium? A. the ability to reproduce independently B. a size greater than 400 nm C. an absence of cell

The property that would indicate that the particle is a virus and not a bacterium is: **C. an absence of cellular machinery** Viruses lack the cellular machinery necessary for independent reproduction and metabolism, which distinguishes them from bacteria. Bacteria are prokaryotic cells with their own cellular machinery that allows them to reproduce independently. In contrast, viruses must invade a host cell and hijack the host's machinery to replicate. As for the other options: - **A. the ability to reproduce independently**: This is characteristic of bacteria, as they can reproduce on their own. - **B. a size greater than 400 nm**: Typically, most viruses range from about 20 nm to 300 nm in size; while some can be larger, there's significant overlap between the sizes of bacteria and viruses. - **D. the presence of DNA**: Both viruses and bacteria can have DNA; some viruses have DNA (like certain bacteriophages), while others have RNA. Thus, the correct answer is C.