The trachea divides into the right and left mainstem bronchi at the:

A physician who specializes in treatment of skin disorders is called a(n):

A) Endocrinologist. B) Gastroenterologist. C) Neurologist. D) Dermatologist.

The ________ is (are) the substance that makes up the cell, with the exception of the nucleus

a. chromosomes b. cytoplasm c. cell membrane d. proteins, lipids, and carbohydrates