Day 60 – DNA Extraction


Science 9 – Today’s lab was to extract DNA from strawberries.  What a wonderful activity to do.  It’s easily accomplished with minimal expenditures, and while the students would not be able to devise the procedure themselves, the steps are somewhat understandable.  Smash the strawberries to break cell walls and membrane.  Soap further breaks down the cells and releases the DNA from the nucleus.  Ethanol makes the DNA percipitate out of the solution.  Heck, I wouldn’t even come up with the procedure.

There were lots of smiles going around the classroom today and there was a good amount of learning. It was good day at school.

Day 51: Extracting DNA


Science 9 – Today in science 9 the students extracted DNA from strawberries.  The lab is fairly straight forward and is well known in education.  With not too much prep, the students are actually extracting DNA – every time I think about this, it blows my mind!  Most of the students find this pretty interesting too.

Of course, this lab is one of those black box type investigations. I have thought about following up the quiz with an experimental design lab.  Some type of investigation that determines how to maximize the quantity of DNA extracted.  Perhaps I will go over an experimental design next class, using the Smarter Science framework.

One of my blocks had several boys that really struggle to stay focused.  Some of them are super interested in this topic and what the lab is about, but have absolutely no desire or compulsion to write something down on paper.  It’s a puzzling thing for me to figure out – I feel like I’m doing all of the things that need to be in place for an engaging environment, but several kids just aren’t in the right head space.

Day 47: KWL Chart on Reproduction


Science 9 – Today was one of those really productive and useful lessons, almost insidious in fact.  Instead of doing an individual KWL sheet, I put students into random groups and had them whiteboard their work. It was a significant improvement over any other KWL activity I have done.  Not only were students able to summarize a fair bit of detail of previous knowledge, the real winner was in the great questions they wondered about and asked about.

I started off this unit with one primary Essential Question: “Why are both meiosis and mitosis required?”  A more thorough inquiry is based on the idea of finding out what meiosis and mitosis are, and what roles organelles, DNA, genes and proteins play.  I’m don’t think I’ve been transparent enough with them about these underlying questions (and they don’t ask), but next day I’ll try to get them to tie these ideas together.

Some of the questions the KWL generated include:

  • What are all the organelles?
  • What do genes do?
  • Why am I different from my parents?

There were many others but I forgot to take pictures of the whiteboard!