Bacteria are prokaryotic cells. simple in structure, they may have both pili and flagella. the flagella are used for movement, but the pili have many functions: adhesion, reproduction, and movement as well. the flagella and pili are similar in that they are both composed of a) elastin. b) lipids. c) microfibrin. d) proteins.

Liquid water turns into water vapor at which step in the water cycle

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. it is known as the "fight-or-flight" hormone. one way that it causes a response in the body is to activate receptors on muscle cells. where are these cellular receptors located? a. on the cell membrane b. in the nucleus c. on the cell wall d. around the mitochondria

What are charcteristics of lithosphere?