Punnett Squares are diagrams used by scientists to help them to figure out how inherited traits (characteristics) will be distributed.
The yellow rectangles show the genes that the parents have.
The genes of the second parent are in the two boxes at the left side of the diagram: a and a.
This parent also has a pair of chromosomes with one of these genes on each one of the pair.
You may want to use Punnett squares to explain how your life forms pass on characteristics, or to help you to figure out what is going on in the Chromosome Kindergarten!
Let's try some samples and see how these squares can help us.
This Punnett Square shows how we can diagram the genes.
The orange bird has two dominant Agenes.
We put two A s along the top of the square.
The blue bird has two recessive a genes.
We put two a s down along the left side of the square.
All the offspring have the genes Aa.
Now suppose that two individuals from the F1 generation become parents.
Here they are!
You can see how their genes work out.
The offspring are coded in the squares.
One bird will be orange with two
What if we are studying more than one characteristic?
In the Punnett Square we have put a symbol for each of the chromosomes that the parent has.
Here we are only counting one gene on each of the two chromosomes. In real life an organism has thousands of genes on each of a number of chromosomes. For example, human beings have 46 chromosomes, and inherit 23 from each parent.
Living things are very complex.