Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: First, notice where carbon is fixed by the enzyme Rubisco. In C-3, C-4, and CAM plants, CO 2 enters the cycle by joining with 5-carbon ribulose bisphosphate to form a 6-carbon intermediate, which splits (so quickly that it isn't even shown) into two 3-carbon 3-phosphoglycerate molecules. Now look for the points at which ATP and NADPH (made in the light reactions) add chemical energy ("Reduction" in the diagram) to the 3-carbon molecules. The resulting glyceraldehyde-3-phosphate "half-sugars" can enter several different metabolic pathways. One recreates the original 5-carbon precursor, completing the cycle. A second combines two of the 3-carbon molecules to form glucose, the universal fuel for life. The cycle begins and ends with the same 5-carbon RuBP molecule, but the process combines carbon and energy to build carbohydrates food for life. Answer: iron and magnesium

Output: What elements do mafic minerals typically include?

Input: Consider Input: Passage: rates The rates at which reactants are consumed and products are formed during chemical reactions vary greatly. We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst. Answer: catalyst

Output: The presence of what, which acts as a trigger, affects the rate of chemical reaction?

Input: Consider Input: Passage: All carbon atoms have six protons. Most also have six neutrons, but some have seven or eight neutrons. What is the mass number of a carbon isotope that has seven neutrons?. Answer: six
Output: All carbon atoms have how many protons?