CHICAGO -

Sex education will be coming to Chicago kindergartners within the next two years.

It's all part of a new policy that was passed by the Chicago Board of Education. It mandates that sex education be taught in every grade, beginning in kindergarten.

It fulfills a proposal President Barack Obama supported when he served in the Illinois state senate in 2003. He later defended the idea when he first ran for president in 2008.

"It is the right thing to do, to provide age-appropriate sex education, science-based sex education in the schools,” said President Obama during a Planned Parenthood Convention in 2007.

Kindergartners in Chicago will now learn about anatomy, reproduction, healthy relationships, and personal safety. Up until third grade, the sex-ed lessons will focus on family, feelings, and appropriate and inappropriate touching. In the fourth grade, students will learn about puberty and HIV. From fifth grade on, the lessons will be on reproduction, sexually-transmitted diseases, and contraception, including abstinence.

For the first time in Chicago, sex-ed lessons will also cover sexual orientation and gender identity.

Parents can opt out of the sexual health education program.

Chicago has the third-largest public school system in the country.