Using hands-on DNA activities in my biology class has been a gamechanger for helping my students understand DNA structure and function. DNA can be a challenging topic for students. It’s not something students can see through a microscope and generally their knowledge of DNA is limited. Students know that DNA is important. They just aren’t sure why.
Introducing DNA To Your Students
I really like introducing DNA through storytelling during my biology lectures. It gives my students some context in a lot of the key experiments and research that lead up to Watson and Crick’s DNA model. We talk about key discoveries on chromosomal inheritance, chargaf’s rules for base pairing, and Rosaland Franklin.
With lecture, I am also bringing in different worksheets to help students better understand the content. Here are some of the activities I like to add to my students’ interactive notebook.
- Lecture Notes
- Base pairing worksheet
- Concept Maps
- Transcription And Translation worksheets
DNA Model 3D Project
The first activity I like to do with my students is my DNA model lab. In this lab I have the students follow a color guide and identify the parts of a nucleotide while matching up the base pairs of the DNA double helix. It’s a simple cut and paste lab in which students build a DNA model with a wire coat hanger and a couple of straws that they cut into 1 inch segments. This lab can be started in class and finished at home or it can be done over a couple of class periods. The end result is that students will have built their own DNA double helix.
DNA Replication Hands On Activity
Once my students have mastered an understanding of the structure of DNA, I teach them how DNA replicates through the semi-conservative model. We use a variety of visuals during lectures, but this is often a difficult concept for students to grasp. My favorite DNA replication hands-on activity is using the DNA replication kit sold by Ward’s science. It includes enough materials for 10 lab stations and it can be used year after year. It’s definitely worth the investment of department funds in my opinion.
In the activity students will build a DNA ladder following the base pairing rules. From there, students will pull apart the nitrogen bases just as the DNA molecule would be “unzipped” with the help of enzymes. Students then do the work of DNA polymerase by adding in complementary parts to build and turn one strand of DNA into two identical strands.
Strawberry DNA Isolation
The third hand-on activity I like to use in my biology class is my strawberry DNA isolation lab. This is a simple grocery store lab where students can use a salt and soap mixture to break down the cell membranes of strawberries and then chilled rubbing alcohol to get the strawberry DNA to precipitate out of solution so it can be observed. The materials list I use fot this lab is simple enough that students could do this lab through independent studies or as a make up assignment.
While human cells are diploid, strawberry cells are octoploid meaning each cell contains 8 copies of its DNA. These extra copies of DNA make strawberries an excellent option for this DNA isolation lab. Students love this hands-on DNA activity as a way to see something that is not normally visible to the naked eye. Teachers love this activity since there is minimal prep work and doesn’t require any dangerous chemicals or extra safety precautions.
Final Thoughts…
If you are looking for ways to get your students involved in the process of learning about DNA, all three of these hands-on activities are great additions to your DNA unit. Labs are always a highlight of biology class and these activities will help your students master this key concept.
