"...your are not a biologist unless you pass the exams that say you are qualified to be a biologist."

No. There are no exams that say you are qualified to be a biologist. When you get paid for being a biologist, you are a biologist. There's no exam that says you qualify to be a parent. You become a parent by having kids.

There are licensed occupations, like cosmetologist, electrician, doctor, and dentist. There are tests you have to take to legally be one of them. There are no licenses for biologist, physicist, politician, or cult leader. Anyone can just go apply for jobs in those fields and if they get hired, they are one.