1. A base found in DNA (but not in RNA) and derived from pyrimidine; pairs with adenine Noun
2. One of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose) Noun
3. A unit of weight equivalent to 1000 kilograms Noun
4. The 20th letter of the Roman alphabet Noun
5. Thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantity; exerts the same biological effects as thyroxine but is more potent and briefer Noun
6. Hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells Noun