Which statement describes bacteria?

Which statement describes bacteria?

• A. Includes powdery mildew and rust.
• B. One-celled microscopic organisms that cause shoot blights, leaf spots, soft rots, and galls.
• C. Commonly spread by aphids, leafhoppers, and thrips.
• D. Large viruses.

Answer: (B)

Bacteria are one-celled microscopic organisms that can cause plant diseases such as shoot blights, leaf spots, soft rots, and galls. This description directly identifies bacteria as single-celled organisms and links them to the kinds of diseases they produce in plants, which is the defining idea being tested. Powdery mildew and rust are caused by fungi, not bacteria, so describing those as bacteria would be incorrect. The statement about being spread by aphids, leafhoppers, and thrips describes how some pathogens are transmitted (often viruses) rather than what bacteria are. Large viruses are not bacteria, since viruses are much smaller and not cellular.

Bacteria are one-celled microscopic organisms that can cause plant diseases such as shoot blights, leaf spots, soft rots, and galls. This description directly identifies bacteria as single-celled organisms and links them to the kinds of diseases they produce in plants, which is the defining idea being tested. Powdery mildew and rust are caused by fungi, not bacteria, so describing those as bacteria would be incorrect. The statement about being spread by aphids, leafhoppers, and thrips describes how some pathogens are transmitted (often viruses) rather than what bacteria are. Large viruses are not bacteria, since viruses are much smaller and not cellular.