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.

Hormones are chemical molecules produced by endocrine glands. one such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles. which two statements describe the probable reason for the function of the hormone? the cells in the heart have specific receptors that allow for the intake of hormones. the heart and the endocrine glands have the exact same types of cells. all cells make the same types of hormones. thyroid hormones show their effect on the heart by means of specialized cells. thyroid cells and cardiac cells have different dna.