The past few days we had studied the circulatory system, so today was the day to make blood. I had all my students bring in plastic water bottles today (I had a few on hand for those that forgot). We started out by making plasma (water, two drops of yellow food colouring, and a bit of salt to represent the minerals and chemicals. (And yes, I did get quite a few comments about it looking like pee in the bottle - I told you, I have a LOT of boys in my class). ;)
We then added our red blood cells. I poured a large amount of Cheerios into a large ziploc bag and added a whole bottle of red food colouring. I mixed it up until all of the Cheerios were red, then let the students add the Cheerios to their bottles. The students already knew that the red blood cells were the most plentiful type of cell in the blood, and the reason why blood appears the colour of red. Like magic, as soon as we added the Cheerios to our bottles, the plasma turned red.
We then added some mini marshmallows to represent the white blood cells and purple pompoms to represent the platelets (both less plentiful then the red blood cells). The finished result was quite gross, but definitely a useful model that my students will remember for a long time.
Because I try to integrate the content areas into Language Arts whenever possible, we turned our bloody experiment into a writing task. The final task was to have my students write an expository paragraph about blood. After a quick minilesson about the set-up of an expository paragraph, I taught my students how to set-up a page to do research. We divided our page into 4 large squares (plasma, red blood cells, white blood cells, and platelets) and watched a BrainPop video about blood. Students had to record facts and research on their page while watching the video (we actually watched the video twice to make sure we got down all the facts ... we LOVE BrainPop in my classroom!). I subscribe to BrainPop on my iPad. I only have one iPad for my classroom (my own which I bring to school everyday. I put my iPad under the ELMO so it projects over the smartboard.
Last step, the students turned their research into an expository paragraph. They needed to include a topic and closing sentence, and at least one sentence in the body for each of the four subtopics (plasma, red blood cells, white blood cells, and platelets). I did encourage my more proficient writers to include at least two compound sentences for each subtopic. They had to illustrate their paragraphs with a labelled diagram of the blood model we made today. A great summative piece to a bloody fun day! ;) (I apologize for the lightness of the pictures here - when my students write in pencil, it's so hard to photograph).