Which group is an ecosystem performs photosynthesis

Which of the following is an example of this type of co-evolution

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

What kinds of molecules can pass through the cell membrane without any problem?