By convention, it has been determined that alpha or significant levels should be set no larger than 0.05. This is considered as the standard value set and agreed by convention for the probability of making a Type I error. Sometimes, 0.01 is used especially for medical related researches.
B. when the immune system attacks the body's own cells
The fact that the two strands of DNA are complementary <span />
C. It can be considered a global ecosystem