________ are the internal cellular structures that perform specific functions essential to normal cell structure, maintenance, and metabolism

Which of the following is an index commonly used to determine relative lung maturity?

a. FRC/TLC ratio b. L:S ratio c. RQ ratio d. SP-A

An athletic-looking individual is likely to be characterized as ________.

A. ectomorphic B. metamorphic C. mesomorphic D. endomorphic