Starting next month, students completing their sophomore year at Howard University Medical School will be expelled if they do not take and pass a national examination teting their competency in basic science.

Dr. Marion Mann, dean of the medical school, said that the new requirement, agreed to in a faculty vote two years ago, is intended to improve the performance of Howard graduates on the national medical licensing examination. Students will havea chance to retake the exam in the fall and gain readmission.

While 93 per cent of Howard's graduates now pass the exam, that success rate places them significantly below the national average of 98 per cent.

To practice medicine, a physician must either pass the national examination or a state exam.

The examination the students, must pass is Part I of the three-part national licensing exam and tests them on such subjects as anatomy, physiology, pharmacology, microbiology and behavioral sciences.

Thirty-five per cent of the nation's 116 medical schools require that students pass the exam to stay in school and move on to working with patients in their junior and senior years.

Georgetown and George Washington, the other medical schools in the city, do not require the examination, but deans at both schools said that 80 per cent of their students take the examination voluntarily at the end of the sophomore year, preferring to be tested on the material while it is fresh, rather than wait two years to take all three parts of the exam at the same time.

"This is an effort by the college of medicine to do its job better," said Mann. "Medical education changes, it isn't a static thing. It's always changing."

According to Dr. L. Thompson Bowles, George Washington's dean for academic affairs, most medical schools used to require that sophomores pass part I of the national licensing exam.

"At the end of the 60's," he said, "there was an increasing trend to drop the requirement that they pass" the exam and instead schools simply required that the students take the examination then at the end of their sophomore year. Those who failed could take the test again when they completed medical school and were ready to be licensed as physicians.

However statistics compiled by the Association of Americans Medical Colleges show schools are again placing importance on the test results.

In the 1973-74 academic year 17 per cent of the nation's medical schools required sophomores to pass the test. The next year it was 23 per cent, then 28 per cent and this year the figure was 35 per cent.

Bowles said GW doesn't use the examination because "we think it's an important exam within limits, but it doesn't necessarily measure the kind of things we're interested in having our students know.

"The ability to take that exam is a straight recall of a factual situation," said Bowles. "We want our students to learn facts, but we're much more interested in having our students manipulate information, to use reasoning."

Under the Howard program, students who fail the test in June will be allowed to pay tuition in the fall and take the exam again. If they pass they will be allowed to continue their education. If they fail, they will have to leave school until they can pass.

The new policy is being protested by two white members of the Progressive Labor Party, Joyce Waite, a nurse at Howard Hospital and Dr. Linda Green, an assistant professor of medicine and assistant professor of oncology (the treatment of cancer) who charges the policy is "racist."

Green said she has been brought up on charges by Mann for circulating a leaflet in which she called for a strike or boycott of the exam by the students.

Asked if Green, a self-described Communist, was going to be fired, Mann said "that's an internal matter that's being handled through the usual channels."

As to the charge that the new policy is racist, Mann, the black dean of the predominently black school, said, "I wouldn't even know how to respond to that."