What are sub-microscopic particles that cause familiar diseases like the common cold?

What are sub-microscopic particles that cause familiar diseases like the common cold?

• A. Viruses
• B. AIDS
• C. HIV
• D. Sanitation

Answer: (A)

The concept being tested is what viruses are. Viruses are tiny infectious particles smaller than bacteria that cause many familiar diseases, including the common cold. They cannot reproduce on their own; they must enter living cells and hijack the cell’s machinery to make more virus particles. Because of their minute size, they’re not visible with standard light microscopes and are studied with electron microscopes. The common cold is caused by several viruses, such as rhinoviruses, and not by an infectious particle like a disease or a public-health measure. While HIV is a virus, it doesn’t cause the common cold, and AIDS is a disease caused by HIV, not the particle itself. Sanitation is a preventive practice, not an infectious particle. So the best answer is the term that names these sub-microscopic infectious agents: viruses.

The concept being tested is what viruses are. Viruses are tiny infectious particles smaller than bacteria that cause many familiar diseases, including the common cold. They cannot reproduce on their own; they must enter living cells and hijack the cell’s machinery to make more virus particles. Because of their minute size, they’re not visible with standard light microscopes and are studied with electron microscopes. The common cold is caused by several viruses, such as rhinoviruses, and not by an infectious particle like a disease or a public-health measure. While HIV is a virus, it doesn’t cause the common cold, and AIDS is a disease caused by HIV, not the particle itself. Sanitation is a preventive practice, not an infectious particle. So the best answer is the term that names these sub-microscopic infectious agents: viruses.