What fraction of u. s. physicians out of total physicians are specialists and subspecialists?

Only 1/3 of US doctors are specialists and subspecialists.

Explanation:

An expert doctor is one who works with a specific field of medicine (such as an endocrinologist who deals only with hormonal issues, for example). A subspecialist doctor is another doctor who specializes in some organ or, what is often occurring, some specific disease.

This type of professional requires a long time of study and a great economic expense with the academic specialization, therefore, there are fewer specialist doctors and subspecialists than genealogical doctors, as general practitioners, who although they study a lot, can practice the profession in a shorter time period. It is estimated that only 1/3 of doctors in the US are specialists and subspecialists.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u