Stem cell research has been a controversial subject in past years. what is the reason for this?
a: cells for study are often taken from human embryos.
b: stem cell techniques will not accomplish the intended purpose.
c: replacement tissue will never be grown from a person's own stem cells.
d: the cells cannot be isolated.

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.