Biology Class: Punnett Squares using littleBits

Using littleBits electronics to build a STEAM project that summarizes the concept of the genetic variations using Punnett Squares.

Using models such as Punnett Squares to describe the cause and effect relationship of gene transmission from parents to offspring and resulting genetic variation.

In this project the student can choose between the genes using Slide Switch Bit; where the
On state stands for the Recessive gene, and the Off state stands for the Dominant gene.

The project displays the color of the flower using Servo Bit; where this motor rotates a circular cartoon disc 90 degrees around to change the position of the colored quarter.


Duration: 2 hours, 4 groups

Credits: Fun Robotics, @mohsh

Middle School (ages 11-13)


Computer Science
General Education
littleBits Basics
Life Science
Makerspace Workshops
Physical Science

branch (6)
usb power (1)
slide switch (4)
double AND (4)
servo (4)
USB Power Adapter + Cable (1)


STEP 1 : Crafting the Punnett Squares

Biology Class

The Punnett Squares technique has 4 squares, we will introduce one to be rebuilt 4 times. Here we need to cut a circular cartoon disc with diameter of 10-15 cm, then fix the Servo hub on the center of that disc, to be connected to the Servo Bit later.

STEP 2 : The Double AND Bit controls!

Biology Class1

Here we will control the Servo Bit of the square using Double AND Bit; where the output of the AND connected to the Servo Bit, and the two inputs of the AND are two Slide Switches (One represents one of the pollen’s genes and the other switch represents one of the Pistil’s genes). *Remember: This connection is only for one square, it should be done 4 times! Where each switch will control two inputs using Branch Bit (Controls two ANDs through the row or through the column).

STEP 3 : The output of the mechanical display

Biology Class2

Now we need to open a circular section on the top of the cartoon square such that it covers one quarter of the inner circular disc; when the rotary disc rotates 90 degrees displays the other color (the purple).

*Remember: on the top of the inner circular disc we need to fix two adjacent quarters; one is white and the other is purple.

STEP 4 : Assembly!

Biology Class3

Finally we need to assemble the four squares together to get one full Punnett Squares model; where the squares will be connected together using wood sticks. *Remember: you have to power up the four switches (the pollen’s and pistil’s sides), use the Split Bit.