Draw students' attention to the key ideas by using posters or overhead transparencies.
Emphasize that DNA molecules have the genetic information and make copies or replicate themselves so that the daughter cells get the same information.
Begin this section with Activity 4-1: Removing DNA from Thymus Cells.
Discuss the composition of nucleotides and how they are organized in the DNA molecule.
Discuss the role of models in science.
Assign Activity 4-2: Building and Using a DNA Model.
Stress the important roles of DNA, mRNA, tRNA, and amino acids in making proteins. Discuss the processes of transcription and translation.
Assign Mini Activity: Coding. The secret message is “HumBio is humming” followed by Apply Your Knowledge. Emphasize how the genetic code is represented by the sequence of triplet nucleotides of DNA molecules.
Select appropriate Projects and other activities if time permits.
Emphasize the big ideas of this section by discussing answers to the Review Questions.
At the end of the section refocus students' attention on the key ideas.