12. Which pair are both structural arbohydrate molecules a starch and glyeogen b. starch and cellulose d cellulose and chitin e. glycogen and chitin of these statements is NOT true about DNA? a. it is the genetic material of the cell b. it forms a double helix e. it contains the sugar ribose d. the paired nitrogen bases are joined by hydrogen bonds 14. The DNA consists of phospholipids and steroids b. nitrogenous bases, amino acids and phosphate groups a. amino acids and unsaturated fats c. d. phosphate groups, nitrogenous bases and sugar. 15. Which statement is true about RNA? it contains adenine paired to thymine a. b. one of the bases from DNA is replaced by uracil c. d. it contains the sugar deoxyribose. It is a double-stranded molecule 16. Carbohydrates normally function in animal as a. the functional units of lipids b. enzymes in the regulation of metabolic processes c. a component of triglycerides d. energy storage molecules. 17· The elerment nitrogen is always present in all of the following EXCEPT a. proteins b. nucleic acids c. amino acids d. DNA e. Starch 18. All of the following are carbohydrates EXCEPT a. lactose b. cellułose c. hemoglobin d. glycogen