a friend claims the Calvin cycle consists ofdark reactions that take place only at night. explain why your friend is incorrect .

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

Which of the following is not a benefit of genetically modified foods? a.pest-resistant crops b.herbicide-resistant crops c.plants that do not require water?

Is genetic diversity the same as genetic variation?