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

[EX Q]: Passage: Young reptiles, like the baby alligator in Figure below , look like smaller versions of the adults. They don't have a larval stage as most amphibians do. Baby reptiles are able to move and search for food but are at high risk of predation. Adult reptiles rarely provide any care for their offspring once the eggs are laid. The only exceptions are female alligators and crocodiles. They defend their eggs and hatchlings from predators and help them reach the water. Answer: larval stage
[EX A]: What developmental stage do alligators lack that most other amphibians have?

[EX Q]: 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
[EX A]: The first period of the paleozoic era was called what?

[EX Q]: Passage: Sickle-Shaped and Normal Red Blood Cells. Sickle cell anemia is an autosomal recessive disorder. The mutation that causes the disorder affects just one amino acid in a single protein, but it has serious consequences for the affected person. This photo shows the sickle shape of red blood cells in people with sickle cell anemia. Answer: autosomal recessive disorder
[EX A]:
Sickle cell anemia is what type of disorder?