CHICAGO -- The Chicago Board of Education approved a policy last week that requires sexual education to be taught to students beginning in kindergarten.

The new curriculum, which spans multiple grade levels, includes lessons on anatomy, healthy relationships, gender identity, human sexuality, sexual orientation, reproduction, and sexually transmitted infections reports CBS Atlanta.

Kindergartners through third graders in the Chicago Public School System "will learn the basics about anatomy, reproduction, healthy relationships and personal safety" with lessons that "focus on the family, feelings and appropriate and inappropriate touching," reports ABC News.

In the fourth grade, the students will begin to learn about puberty and sexually transmitted infections. In the fifth through 12th grade, the lessons focus on reproduction, sexually-transmitted diseases, contraception, and bullying.

This is the first time that the Chicago Public School System’s sex education will include topics on gender identity and sexual orientation, reports ABC News. The school board says it is to prevent bullying and promote tolerance.

Most public schools in the country begin teaching sex education in fifth grade, according to ABC News.

Parents will have the ability to opt-out of the sex education program for their students.

The program is expected to begin in 2016.