The area of land from which water drains into a river

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

We all have different forms of genes from our parent(s).what are these different forms called? a.alleles b.characters c.dna d.resources

What is the next step in muscle contraction after the actin changes shape