Option 1 (alternative approach):
Step 1: Nucleic acids are the acidic biomolecules present in the chromatin material of cell nuclei. On complete hydrolysis a nucleic acid yields a nitrogen base, a pentose sugar and phosphoric acid, which shows that it is a polymer of nucleotides linked through phosphodiester bonds.
Step 2: Comparing the two kinds point by point:
DNA: sugar is deoxyribose; the pyrimidine base thymine is present; it exists as two complementary strands wound into a double helix; found chiefly in the nucleus; its amount is fixed for a given species.
RNA: sugar is ribose; uracil takes the place of thymine; it is mostly a single strand; found in both nucleus and cytoplasm; its amount can vary.
Step 3: Roles in the body: DNA carries the genetic code and copies itself during cell division, which is the basis of heredity; the RNA molecules (messenger, transfer and ribosomal RNA) read this code and assemble amino acids into proteins, that is, protein synthesis.
Option 2 (alternative approach):
Step 1: Vitamins are accessory food factors needed only in very small amounts for normal growth and health. The property chosen to classify them is solubility, which splits them into a fat-soluble set and a water-soluble set.
Step 2: The fat-soluble members are easily remembered as A, D, E and K. Because they are stored in body fat and the liver, an excess is not thrown out quickly. A clearly named fat-soluble vitamin is Vitamin D (calciferol).
Step 3: Out of this fat-soluble group, Vitamin K is the one that helps blood to clot; when it is lacking, the blood takes much longer to clot.
Step 4: The water-soluble group (the B-complex and vitamin C) is not stored, so it must be taken in the diet every day.