Concept:Bacteria are microscopic organisms that can be seen only under a microscope, have measurable sizes, are classified by shape, and many species can cause disease.
Explanation:Bacteria are prokaryotic microorganisms, so they are visible only under a microscope.
Their cells typically range from about
0.5μm to
5μm in diameter.
They are grouped according to their cell shapes, such as cocci, bacilli, and spirilla.
Although some bacteria are harmless or useful, many bacteria cause diseases like cholera and tuberculosis.
Thus, the statement "they do not cause disease" is not a true characteristic of bacteria.
Answer:The correct option is D. Bacteria do cause disease, so D is the exception.