Thursday, October 25, 2012

Blood! (Making a Model)

It’s almost Halloween so a little gore is a good thing, right?! Plus, it’s been ages since my son and I have done any human body-related science activities.

Within the last week or two, my son and I have had conversations about both scabs and white blood cells. This activity is the perfect complement to those discussions.

We made a model of blood! 

Here’s what we used:
4 teaspoons of yellow jello powder
1/3 cup of boiling water
½ cup of cold water
½ cup plus 1 tbsp. of red Perler beads
50 tiny clear seed beads
1 white 9-millimeter pony bead
Liquid measuring cups
Clear glass bowl

This activity came from the amazing book Squirt! The Most Interesting Book You’ll Ever Read About Blood by Trudee Romanek.

It is chock full of astonishingly awesome facts about the blood in our bodies, explaining everything from scab science to blood types (O, A, B, or AB), bone marrow, leeches, how blood is pumped through the heart, and more. Comprehensive is an understatement!

While there was a lot that was too advanced for my son, there was a lot that wasn’t. I simply stuck to the things I knew he’d understand.

Romanek’s book taught us the “blood basics:”
Most of our blood is plasma, which contains nutrients from food, hormones, proteins, etc.
White blood cells fight germs and illness.
Platelets stop an injury from bleeding.
Red blood cells carry oxygen.

How to Make a Blood Model
Step 1: Mix 4 teaspoons of yellow jello powder with 1/3 c. boiling water. Stir until dissolved.

Step 2: Add ½ cup cold water. Stir. Then pour into a clear glass bowl and place in the refrigerator for 1 hour.

Step 3: Remove from the refrigerator. The jello will be thicker but not set. Stir in the red beads (aka red blood cells).

Step 4: Add the white bead (aka white blood cell) and clear beads (aka platelets). Stir.

Your model of blood will show you how much red and white blood cells and platelets are floating in your blood’s plasma!

Draw it!
To keep my son from forgetting the make-up of blood, he drew a picture of his model on a worksheet I made. 

Download a PDF of this worksheet here.
Inside his large drop of blood was 1 huge white blood cell, several large red blood cells, and a few small purple platelets, all floating in yellow plasma.

How Much Blood is in Your Body?
The average person has 70 milliliters (ml) of blood for every kilogram they weigh, according to Romanek’s book.

My son weighs 46 pounds (he’s a skinny mini) or 20.865232 kilograms (kg).
70 ml x 20.865232 kg = 1,460.6 ml of blood (or almost 1 and a half liters)!!

Check out our other human body-themed activities:


  1. Ooooh such a cool science activity for Halloween! I think I would enjoy this as much as the kids. :-)

  2. This looks amazing. I will have to get my hands on that book. Thanks for sharing.