Red blood cells have and generate energy
a. mitochondria; anaerobically
b. no mitochondria; anaerobically
c. mitochondria; aerobically
d. no mitochondria; aerobically
e. none of the above

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;

the answer is z.

the human body has five levels of organization. level 1: cells. cells are the basic units of life and form the first level of organization. cells in the human body have specific functions. examples include nerve cells, blood cells, liver cells, and so on.