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

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
Gametes swim with the aid of what structure to the female gametangium, and fertilization ensues?

Passage: Power plants are where electric power originates. They have electric generators that generate electric current through electromagnetic induction. Answer: power plants
Where does electric power originate?

Passage: Suppose that you wanted to know how many hydrogen atoms were in a mole of water molecules. First, you would need to know the chemical formula for water, which is H 2 O. There are two atoms of hydrogen in each molecule of water. How many atoms of hydrogen would there be in two water molecules? There would be 2 2 = 4 hydrogen atoms. How about in a dozen? In that case a dozen is 12 so 12 2 = 24 hydrogen atoms in a dozen water molecules. To get the answers, (4 and 24) you had to multiply the given number of molecules by two atoms of hydrogen per molecule. So to find the number of hydrogen atoms in a mole of water molecules, the problem could be solved using conversion factors. Answer: water
H2o is the chemical formula for what?