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

[EX Q]: Passage: gametes swim with the aid of their flagella to the female gametangium (the archegonium), and fertilization ensues. The zygote grows into a small sporophyte still attached to the parent gametophyte. It will give rise, by meiosis, to the next generation of spores. Liverwort plants can also reproduce asexually, by the breaking of branches or the spreading of leaf fragments called gemmae. In this latter type of reproduction, the gemmaesmall, intact, complete pieces of plant that are produced in a cup on the surface of the thallus (shown in Figure 25.11)are splashed out of the cup by raindrops. The gemmae then land nearby and develop into gametophytes. Answer: flagella
[EX A]: Gametes swim with the aid of what structure to the female gametangium, and fertilization ensues?

[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: Cynodonts probably gave rise to mammals about 200 million years ago. However, they are not considered to be mammals themselves. In fact, competition with early mammals may have led to their extinction. They went extinct sometime during the Jurassic or Cretaceous Period. Answer: mammals
[EX A]:
Competition with what emerging animal group may have led to extinction of cynodonts about 200 million years ago?