Q1. Organisms typically have 20 aminoacyl tRNA synthetases that charge a tRNA molecule with a particular amino acid. One would expect there to be 20 tRNAs: one for each amino acid.

Though, there are 61 known tRNA molecules. What characteristic of the synthetases explains this discrepancy?

Q2. Tina is consuming 15 mg of iron per day. Her RDA is 18 mg. She has no condition warranting a greater-than-normal need for iron. Which of the statements is true about her consumption of this nutrient.