A major teachers union wants to create a rigorous professional exam for K-12 teachers that would serve the same function as the bar exam for lawyers and board certification for doctors.

“Unlike law, medicine, architecture and engineering, we hand teachers the keys and tell them to go into the classroom and do their thing,” said Randi Weingarten, president of the American Federation of Teachers, who is expected to announce the plan Monday. “This is about raising the standards of our profession and making sure that kids get teachers who are prepared.”

A task force of teachers and education experts Weingarten assembled spent a year developing recommendations to improve teacher preparation and certification.

Under the AFT plan, prospective teachers who have undergone training at an education school would have to demonstrate knowledge of their subject areas, an understanding of the social and emotional elements of learning, and spend a year in “clinical practice” as a student teacher before passing a rigorous exam.

The plan also calls for universities to grow more selective in accepting students into teacher preparation programs, requiring a minimum of a 3.0 grade point average to enroll and to graduate, among other things. There are about 1,400 teacher preparation programs in the country, with a wide range of quality, experts say.

“Some ed schools do a great job, some do not,” Weingarten said. “If we as a profession can come to the point where we say ‘This is what we believe a new teacher needs to know or be able to do on her first day of teaching,’ then we can back map this to the ed schools, so that they can design preparation so that it’s aligned with the professional standards.”

Historically, each state sets the qualifications for teachers.

“State standards are all across the map,” said Ron Thorpe, president and chief executive of the National Board for Professional Teaching Standards, the nonprofit independent organization that certifies experienced teachers. “It really is a crazy quilt.”

The AFT wants the National Board for Professional Teaching Standards to develop the actual “bar exam,” a challenge that Thorpe has embraced and said he thinks could be accomplished within five years.

The proposal for a bar exam comes during a period of increased scrutiny of teachers. Encouraged by the Obama administration, dozens of states have begun implementing new teacher evaluation systems. Education Secretary Arne Duncan has expanded that scrutiny to teacher preparation programs at universities, suggesting as recently as last week that many programs are inadequate.

“We have to look to the states that have been approving teacher ed programs for 100 years or maybe longer,” said Susan Fuhrman, president of Teachers College at Columbia University. “And have closed very, very few — even though they have found some wanting — either because of politics or economics.”

At the same time, alternative teacher preparation programs have sprouted up, offering a streamlined path to certification and the classroom. Teach for America, for example, gives college graduates five weeks of training before sending them into some of the most troubled schools in the country.

A bar exam would “just level the playing field,” Weingarten said. “Maybe all the alternative certified teachers will pass with flying colors. But if only 10 percent of TFA passed it and 90 percent of the students from Teachers College passed it, that would say something.”