Homeostasis. The biological definition of homeostasis is âthe tendency of an organism or cell to regulate its internal environment and maintain equilibrium, usually by a system of feedback controls, so as to stabilize health and functioningâ.ositive feedback mechanisms. A positive feedback mechanism is the exact opposite of a negative feedback mechanism. With negative feedback, the output reduces the original effect of the stimulus.
Bacteria produce disease in one of two general ways; some bacteria damage the cells and tissues of the infected organism directly by breaking down the cells for food, other bacteria release toxins (poisons) that travel throughout the body interfering with the normal activity of the host. Pathogens.
There are many kinds of bacteria, some which cause deadly diseases and some which are helpful to man. Those which are harmful cause diseases in man, animals, and plants. They can cause food to spoil, even poisoning people who eat them. But there are a great many bacteria that man and nature use in helpful ways. For example, bacteria play an important role in making buttermilk, sauerkraut, cheese, and vinegar by causing a chemical change called fermentation. Bacteria also attack dead plants and animals, and break them down into nourishment for the soil. Bacteria are even used to purify water in sewer treatment plants!