Which condition is a biotic factor of an aquarium ecosystem? algae growing on the glass

amount of oxygen in the water

temperature of the water

gravel on the bottom of the aquarium

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food