The first one is the correct way to use it, since it separates the parts of the sentence into fragments that can still be understood without changing the meaning of the entire sentence.
Explanation:
Think about what the topic is about and then pick a question you are asking yourself about after that. (Example: you read about Anne Frank, it was about her life in the Annex. Okay here is a question What was Anne relationship like with everyone else in the Annex?
1)The reader might know what John is thinking, but not mom.
2)Creon's discovery that Antigone has hanged herself in her jail cell
The answer is flagellum; flagella
