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

Ex Input:
Passage: Chapter 23 1 Figure 23.5 All eukaryotic cells have mitochondria, but not all eukaryotic cells have chloroplasts. 3 Figure 23.18 C 4 D 6 C 8 D 10 B 12 C 14 A 16 A 18 Eukaryotic cells arose through endosymbiotic events that gave rise to the energy-producing organelles within the eukaryotic cells such as mitochondria and chloroplasts. The nuclear genome of eukaryotes is related most closely to the Archaea, so it may have been an early archaean that engulfed a bacterial cell that evolved into a mitochondrion. Mitochondria appear to have originated from an alpha-proteobacterium, whereas chloroplasts originated as a cyanobacterium. There is also evidence of secondary endosymbiotic events. Other cell components may also have resulted from endosymbiotic events. 20 As an intestinal parasite, Giardia cysts would be exposed to low pH in the stomach acids of its host. To survive this environment and reach the intestine, the cysts would have to be resistant to acidic conditions. 22 By definition, an obligate saprobe lacks the ability to perform photosynthesis, so it cannot directly obtain nutrition by searching for light. Instead, a chemotactic mechanism that senses the odors released during decay might be a more effective sensing organ for a saprobe. 24 The trypanosomes that cause this disease are capable of expressing a glycoprotein coat with a different molecular structure with each generation. Because the immune system must respond to specific antigens to raise a meaningful defense, the changing nature of trypanosome antigens prevents the immune system from ever clearing this infection. Massive trypanosome infection eventually leads to host organ failure and death. Answer: chloroplasts

Ex Output:
All eukaryotic cells have mitochondria, but not all eukaryotic cells have what?

Ex Input:
Passage: Monarch butterflies gather in large groups as they migrate 2,500 miles south each fall. They return to the north in the spring. This migration is a cycle that repeats every year. Answer: migration

Ex Output:
What do we call the seasonal movement of animals?

Ex Input:
Passage: The last step in a scientific investigation is communicating what you have learned with others. This is a very important step because it allows others to test your hypothesis. If other researchers get the same results as yours, they add support to the hypothesis. However, if they get different results, they may disprove the hypothesis. When scientists share their results, they should describe their methods and point out any possible problems with the investigation. Results can be communicated in various ways. A scientist usually contributes material through publication in a peer-reviewed scientific journal. Peer-review ensures the material is of an acceptable quality for the scientific community. Scientists also write review articles, book chapters, and even whole books. They also regularly participate in scientific meetings, presenting their material in front of large audiences of their peers. Answer: communicating findings

Ex Output:
What is the last step in a scientific investigation?