Why do we need to breathe and eat

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Previous pagenext pagepage 3 ofquestion 3 (1 point)which of the following consist of cells that do not have a nucleus? of the above

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