How do viruses make us feel ill?

How do viruses make us feel ill?

• A. They stay outside cells and multiply
• B. They remove nutrients from cells
• C. They cause immediate allergic reaction
• D. They live and reproduce inside our cells, damaging them

Answer: (D)

Viruses make us feel ill by infecting our cells and using those cells to reproduce. After a virus attaches to and enters a host cell, it hijacks the cell’s own machinery to copy its genetic material and assemble new virus particles. This manipulation damages the host cell and often kills it, releasing more viruses to spread. The symptoms we experience—fever, aches, fatigue—come from both the direct damage to cells and the immune system’s response to the infection. That’s why the idea that viruses live and reproduce inside our cells, damaging them, best explains how viruses cause illness. The other ideas don’t fit the main mechanism: viruses don’t multiply outside cells, they don’t primarily remove nutrients from cells, and an immediate allergic reaction isn’t the typical cause of viral illness.

Viruses make us feel ill by infecting our cells and using those cells to reproduce. After a virus attaches to and enters a host cell, it hijacks the cell’s own machinery to copy its genetic material and assemble new virus particles. This manipulation damages the host cell and often kills it, releasing more viruses to spread. The symptoms we experience—fever, aches, fatigue—come from both the direct damage to cells and the immune system’s response to the infection. That’s why the idea that viruses live and reproduce inside our cells, damaging them, best explains how viruses cause illness. The other ideas don’t fit the main mechanism: viruses don’t multiply outside cells, they don’t primarily remove nutrients from cells, and an immediate allergic reaction isn’t the typical cause of viral illness.