Final answer:
The term 'depletive bacteria' is not a recognized classification and does not represent a type of bacteria that can cause illness, while anaerobic, aerobic, and facultative anaerobic bacteria are known classifications and can be associated with diseases. correct option is a.
Step-by-step explanation:
The question asks which type of bacteria listed is not known to cause illness. The options provided are examples of metabolic classifications based on bacteria's oxygen requirements. These are:
Depletive bacteria
Anaerobic bacteria
Aerobic bacteria
Facultative anaerobic bacteria
'Depletive bacteria' is not a recognized classification of bacteria and is likely a typo or an invented term. The three valid types listed, anaerobic, aerobic, and facultative anaerobic bacteria, can all potentially cause illness depending on the species and context.
Aerobic bacteria require oxygen for survival. Anaerobic bacteria thrive in environments without oxygen, which can include certain habitats in the human body. Facultative anaerobic bacteria can live with or without oxygen, which means they are very versatile and can be found in various environments, including the human gut.