Punnet Squares

What are they?

The Punnet Square is a diagram to discover all the possible combinations of gene types that can occur in babies that are passed on from the parents.

How the Punnet Square works

First, you place the father's alleles on top of the Punnet Square with a letter above each box. Second, you place the mother's alleles on the left side of the Punnet Square with one letter next to the two left hand side boxes. Then, write a two-letter gene combination from the mother's and father's alleles in each of the squares.

In our example the squares are filled like this:

• Top left square: Bb
• Top right square: bb
• Bottom left square: Bb
• Bottom right square: bb
• Notice how traditionally, the dominant alleles (capital letters) are written first 

You can learn more about Punnet Squares by Clicking Here to do a virtual lab on them.

For more information go to: 

http://anthro.palomar.edu/mendel/mendel_2.htm

http://utahscience.oremjr.alpine.k12.ut.us/sciber00/7th/genetics/sciber/punnett.htm
http://www.bugaco.com/calculators/punnett_square.php#kind=blood
https://www.youtube.com/watch?v=prkHKjfUmMs

Meiosis

   Meiosis is a type off cell division that reduces the number of chromosomes. It's referred to as reductive division. It goes through a cycle similar to mitosis, which is cell division, and it has two consecutive cell divisions- Meiosis 1 and Meiosis 2. During this cycle diploid cells turn into haploid cells.

   Chromosomes are structures that contain genetic material passed down from generation to generation. The DNA in chromosomes is arranged in segments genes. These help to decide what you will look like and act like.

   Homologous Chromosomes are chromosomes that make up a pair, one from each parent. These are what gives different options for what child could end up to be like.

   Technology has developed that could help you decide different characteristics of your child. These are called Designer Babies which could prevent disease for your child. With Designer babies you could also actually choose the sex of your child.
   Understanding Designer Babies could help you decide whether you want one or not.