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.
Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit across a pencil eraser. Most bacteria won't hurt you - less than 1 percent of the different types make people sick. Many are helpful. Some bacteria help to digest food, destroy disease-causing cells, and give the body needed vitamins. Bacteria are also used in making healthy foods like yogurt and cheese. But infectious bacteria can make you ill.