What makes the rough endoplasmic reticulum rough? A) It is covered with tiny flagella. B) Its surface is highly folded to increase surface area. C) It is covered with cilia. D) It has a high density of receptor proteins in its membrane. E) It is covered with ribosomes. A buffer is a chemical that: A) can quickly absorb excess H^+ ions to keep a solution from becoming too acidic. B) can quickly release H^+ ions to counteract any increases in the OH^- concentration in a solution. C) is identical to baking soda. D) restores the pH of a solution to 7.0. E) a) and b) are both true. A complex polymer built of monosaccharides is called a(n): A) protein. B) aldehyde. C) polysaccharide. D) polypeptide. E) ketone. Which statement is NOT part of the modern cell theory? A) Cellular reactions include both energy-releasing and biosynthetic types. B) Cells contain hereditary information that passes from one generation of cells to the next. C) The first cell arrived on earth from outer space. D) Cells arise from other cells. E) All living organisms consist of one or more cells. In DNA, adenine from one strand binds to _____ in the complementary strand. A) thymine B) uracil C) guanine D) cytosine E) adenine