Employers Can Not Discriminate Against Applicants

I replied to an internet employment ad on craigslist. Among other things, the application requested my gender and age. Is this legal?

By Deskin Law Firm
Discrimination law does protect the rights of applicants. It can be against the law to ask specific questions about gender, age, race, national origin, medical history, workers compensation claims and other protected areas.

Am I Protected Against Discrimination Just For Applying for a Job?