How does the invasion of bacteria affect the body's immune system?

The body's immune system thinks what he/she is eating or inhaling is a pathogen.  The immune system sends white blood cells to attack.  This triggers an allergic reaction

Explanation:

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.