Final answer:
Anaerobic bacteria can only grow in the absence of oxygen, while vegetative cells are responsible for bacterial growth and infection. Water activity is a measure of available water in food and affects bacterial growth.
Step-by-step explanation:
Anaerobic bacteria refers to bacteria that can only grow in the absence of oxygen. These bacteria are adapted to survive in oxygen-deprived environments and can cause food-borne illnesses. On the other hand, vegetative cells are bacteria that are able to grow and divide, and they are responsible for bacterial growth and infection. Finally, water activity is a measure of the amount of available water in a food, which is important for the growth and survival of bacteria.
Learn more about Food-borne illness