Draw students' attention to the key ideas by using posters or overhead transparencies.
Review mitosis and, if necessary, complete Activity 4-1: Cell-Division Double or Nothing.
Discuss mitosis and introduce meiosis before beginning Activity 4-2: Meiosis and Fertilization.
Review the role of models in science as they are used to help learn about and explain important biological life processes such as cell division.
Discuss the Apply Your Knowledge question dealing with the relationship between DNA replication and chromosomes.
Select appropriate Projects if time permits.
Review the big ideas of this section by discussing student answers to the Review Questions.
At the end of the section refocus students' attention on the key ideas.