The smallest unit of an element that still retains the chemical and physical properties of that element is called:
In an atom, the number of protons always equals the number:
The atomic number of an atom is determined by the n
The _ secretes hormones that are released into the bloodstream to effect target cells.
_ glands that secrete products directly into the bloodstream without ducts and _ glands possess ducts and
secrete their products into their ducts.
The innermost layer of an artery is known as the _.
Which of the following blood vessels are the only ones small, thin, and porous enough to exchange substances at the
tissue level of organization?
When dissecting a specimen,