Bacteria are the group of microscopic, single-celled organisms that inhabit virtually all environments, including soil, water, organic matter, and the bodies of multicellular animals. Bacteria may have spherical, rodlike, or spiral shapes. They also can

BACTERIA
Bacteria are the group of microscopic, single-celled organisms that inhabit virtually all
environments, including soil, water, organic matter, and the bodies of multicellular animals.
Bacteria may have spherical, rodlike, or spiral shapes. They also can be divided into two
main groups, gram-positive or gram-negative. Many bacteria swim by means of flagella. The
DNA of most bacteria is found in a single circular chromosome and is distributed throughout
the cytoplasm. Though some bacteria can cause food poisoning and infectious diseases in
humans, most are harmless and many are beneficial. They are used in various industrial
processes, especially in the food industry (e.g., the production of yogurt, cheeses, and
pickles).
1. Where can one find bacteria?
2. What shapes may bacteria have?
3. Can bacteria be divided into groups?
4. Are bacteria harmful?