Final answer:
Bacteria can infect us through various routes and cause illness. Our immune system fights against bacterial infections.
Step-by-step explanation:
Bacteria can infect us by entering our bodies through various routes, such as through the respiratory system when we inhale contaminated droplets or through the digestive system when we consume contaminated food or water. They can also enter through cuts or wounds on our skin. Once inside our bodies, bacteria can cause infections by releasing toxins or multiplying rapidly, leading to symptoms of illness.
In response to bacterial infections, our immune system puts up a fight. The immune system recognizes the presence of bacteria as foreign and activates immune cells to destroy the invading bacteria. These immune cells can engulf bacteria, produce antibodies to neutralize them, and release chemical substances to kill the bacteria.