the molecule that precedes the electron transport chains of both photosystem 1 and photosystem 2 is an electron acceptor. what is the original molecule that is the electron donor for both of these systems.

During which phase does earth see more than half of the moon's surface? 1)first quarter2)third quarter3)waxing gibbous4)waning crescent

Aperson is outside exercising. body temperature begins to rise, and the person starts to sweat. their body temperature then returns to normal, and the body stops sweating. a positive b negative c allosteric d homeopathic

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.