What is an antigen? Antigen refers to any foreign substance which on entering the body  stimulates the production of antibodies in the body of the  individual as a part of the immune response.
Gen Z Defined. Gen Z consumers range from ages 2 to 19, though the target range for marketers lies from ages 11 to 16. Gen Z is the most diverse and multicultural of any generation in the U.S. -- 55% are Caucasian, 24% are Hispanic, 14% are African-American and 4% are Asian. Gen Z Beliefs.
Generation X Ages | How Big Is Generation X? The age range for Generation X as of 2016 is 35 to 55 (my broadest definition). In 2011, the first Gen-Xer turned 50 years old and the youngest turned 30. We are currently the âsandwich generationâ in America. We are caring for aging parents and raising more than 50 percent of the nationâs children under 18.