Barry is applying the principles of relative dating to a building that has been constructed. Analyzing a section of the building, Barry says that the lowest part of the section must have been constructed the parts above it were constructed. He bases this conclusion on the principle of . Also, looking at a crack forming in the building wall, he says that the crack must be the wall. Barry used the principle of to arrive at this conclusion.

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

An organ system consists of a group of organs that performs specific functions necessary for the survival of an organism. humans have eleven different organ systems: integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. discuss the function of neurons, the brain and the spinal cord within the human nervous system while explaining the interrelationship of each organ.

When the cell concentrates potassium within, against the natural tendency of matter, it is performing a.passive diffusion b.facilitated diffusion c.active transport d.pinocytosis