Question

bacteria and viruses can both invade the human body and cause infection. which best describes how bacteria and viruses are different?
a. bacteria are nonliving organisms, while viruses are living organisms
b. viruses are nonliving organisms, while bacteria are living organisms.
c. bacteria are always harmful, while viruses are always beneficial
d. viruses are always harmful, while bacteria are always beneficial.

Explanation:

• Bacteria are single - celled living organisms. They can reproduce on their own, carry out metabolic processes (such as respiration and digestion of nutrients), and respond to stimuli.
• Viruses are non - living. They cannot reproduce on their own (they need a host cell's machinery for replication), do not have their own metabolic systems, and are essentially just genetic material (DNA or RNA) surrounded by a protein coat.
• Option A is incorrect because it mislabels bacteria as non - living and viruses as living.
• Option C is wrong as bacteria are not always harmful (e.g., some gut bacteria are beneficial for digestion) and viruses are not always beneficial.
• Option D is incorrect because bacteria are not always beneficial (pathogenic bacteria cause diseases) and viruses are not always harmful (though most are associated with harm, the concept of "always" is inaccurate).

Answer:

B. Viruses are nonliving organisms, while bacteria are living organisms.