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

Example Input: Passage: Diagram of a typical prokaryotic cell. Among other things, prokaryotic cells have a plasma membrane, cytoplasm, ribosomes, and DNA. Prokaryotes do not have membrane-bound organelles or a cell nucleus. Answer: not membrane-bound
Example Output: What are unique about prokaryotic cells' organelles?

Example Input: Passage: The first period of the Paleozoic Era was the Cambrian. By the beginning of the Paleozoic, organisms evolved shells. Shells could hold their soft tissues together. Shells could protect them from predators and from drying out. Some organisms evolved external skeletons. These are called exoskeletons . Organisms with hard parts also make good fossils. Fossils from the Cambrian are much more abundant than fossils from the Precambrian. Answer: cambrian
Example Output: The first period of the paleozoic era was called what?

Example Input: Passage: The blood picks up oxygen in the lungs and carries it to cells throughout the body. Answer: oxygen
Example Output:
What does blood pickup from the lungs to be carried throughout the rest of the body?