Preview · the opening missionRead this to the class:
Every cell in a strawberry holds a set of instructions for building a strawberry. The instructions are written in a molecule called DNA. People talk about DNA all the time, on TV shows and in the news, but almost nobody has seen it with their own eyes. Your team's job: get the DNA out of a strawberry's cells, and explain how you did it.
Teams of three, with rotating jobs: Masher (works the bag), Filterer (handles the filter and cup), Recorder (times each step and writes what they see).
Look inside the PDF
Sample pages, stamped “preview”. The download is the clean, full lesson.
In the full lesson PDF
- Predict (5–10 min)
- Hunt (20 min)
- Reveal (10–15 min)
- Act (10 min)
- Background for the teacher
- Assessment
- Student sheet
On the student sheet
- My prediction
- What we saw
- Draw it
- Instructions for a Grade 5 class
- Claim, Evidence, Reasoning
- Exit ticket
US Letter, prints cleanly in black and white. The student sheet is on its own page, ready to photocopy.
Free with an account (any 3 lessons), or US$19 / C$25 for all 4 lessons in this unit.
What students show by the end
- Follows the procedure
- Explains each ingredient
- Uses evidence (CER)
From the lesson’s rubric, which scores each one as not yet, getting there or got it.
Questions teachers ask
How long does “Can you pull DNA out of a strawberry?” take?
50–60 min. Group size: teams of 3.
How much prep does it need?
20 minutes: chill the sealed bottle of rubbing alcohol in a tub of ice (or the freezer) for at least an hour. Mix the extraction solution: 400 mL (about 1 2/3 cups) water, 40 mL (about 3 tablespoons) dish soap and 2 teaspoons salt, stirred gently so it doesn't foam. For the no-soap test, mix a pinch of salt into 30 mL (2 tablespoons) of water. Hull the strawberries. Set up one tray per team.
What materials do I need?
Strawberries, fresh or frozen and thawed; zip-top freezer bag, sandwich size; clear liquid dish soap; table salt; rubbing alcohol (isopropyl, 70% or stronger), ice cold, teacher-handled; coffee filter and a funnel or cup to hold it; and 4 more. Cost: about $20 for a class of 30.
Which curriculum standards does it cover?
NGSS (US): MS-LS1-2 (partly). It also matches Ontario Science and Technology, Grade 8.
What’s in the lesson PDF?
A teacher guide that walks you through predict, hunt, reveal, act, background for the teacher and assessment, then a student sheet (“My prediction”; “What we saw”; “Draw it”; “Instructions for a Grade 5 class”; “Claim, Evidence, Reasoning” and “Exit ticket”) on its own page, ready to photocopy. It’s US Letter and prints cleanly in black and white.
Can I try it for free?
Yes. A free account includes any 3 full lessons of your choice, and this can be one of them. After that, this unit is US$19 (C$25) for all 4 lessons, yours to keep, or every lesson is US$79 (C$109) a year.