Unit 9 deals with genetics, by far the most abstract material in the book. Some teachers may opt to "save" some

of this information for later years, or to use the lessons to challenge their most motivated students.

​

This 5-page lesson (including a lab and the review questions) deals with a topic that a large percentage of middle school children find fascinating - the means by which gender is determined. 

​

The opening story introduces children to the concept of gender identity, and links this topic with the concept of bias

(that was introduced early in the course).