Open this lesson with a discussion on birth defects. Break the class into groups to visit a website and learn about what happens at each stage of human embryo and fetal development. Assign each group a particular birth defect to research and create a slide show to present to the rest of the class. Note that in Step three of the lesson plan, the PowerPoint that you are supposed to show is not included. There are, however, a student worksheet and group presentation grading rubric.