IOWA CITY, Iowa — The University of Iowa has become the nation’s first public university to include optional questions about sexual orientation and gender identity on its application, a move hailed Wednesday by advocates hoping to improve the college experience for gays and lesbians.

University officials say the move sends a strong signal that they value the diversity that gay, lesbian, bisexual, and transgender students bring to campus. They say that knowing some students’ sexual orientation will allow them to track their enrollment and graduation rates and promote housing, student groups, and programs that might improve their social and academic success.