Which of the following best describes chemical weathering

What is used to keep track of the gamates and possible offsprings combination

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

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