Learning Exercise

What is DNA?

In this activity students extract DNA from bananas. They will see that DNA is a component of living things and that DNA can be extracted and observed.
Course: 7th Grade Life Science/ High School Biology

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Technical Notes

This lesson contains 3 parts: Part 1 is a 10-15 minute lecture on DNA. The second part is 20 minutes on the DNA extraction activity. Part 3 will allow students to reflect on what they have learned by answering questions and writing a quick summary of what they did.


Students should have a basic understanding of the cell theory.


This activity will cover what DNA looks and feels like. Students will be given a short lecture before the activity on what components make up DNA and the function of DNA.

Learning Objectives

Meets California Standards: 5.The genetic composition of cells can be altered by incorporation of exogenous DNA into the cells. As a basis for understanding this concept: Students know the general structures and functions of DNA, RNA, and protein.


Ask students to Draw their white threads of DNA. The following questions may be asked: 1) Describe the appearance of DNA extracted. 2) From your experiment can you describe what is a precipate? 3) Write a conclusion on what you have learned about DNA from our unit. 4) Do you think your results would be different if you were to use a fruit or vegetable other than bananas? Explain.