BROOKLYN - A new mandate calls for schools to devote a course to sex education in sixth or seventh grade, and again in ninth or tenth grade, officials revealed Tuesday.

Students will participate in discussions on topics such as pregnancy, how to use a condom and the appropriate age for sexual activity. Parents will be able to have their children opt out of the lessons on birth-control methods.

The classes will begin next spring and could be incorporated into existing health education courses, according to school officials.