Punnett squares!!!!!!

In class we have began the study of genetics.  Genetics is the study of  heredity.  In addition to the fun activities we have done for genetics so far, we also began punnett square.  Punnett squares shows the probability of what alleles can occur when people cross genetics.  This all started from a scientist named Gregor Mendel.  Mendel observed pea plants and noticed that some pea plants had the same and different traits from there parents.  This discovery triggered another one.  When a new organism is made the process of fertilization is formed.  Fertilization is when a egg and a sperm is joined together to create a organism.  Another would for fertilization for pea plants is pollination.  Mendel was a smart man and he wonder; what happened if you cross pollinate?  The hypothesis lead to the activity of cross pollination.  Mendel took one tall pea plant and instead of pollinating it into the same type of pea plant he pollinate it into a different type of pea plant;a small pea plant.  In a couple of days Mendel check the pea plants and it seemed that one plants was three fourths bigger than the other.  Mendel tried again and this time he cross pollinated with four plants instead of two plants.  The results was three-fourths of the plants was tall.  Mendel was intrigued with the results which began the study of punnett squares. 

Gregor Mandel known for his discovery of cross pollination.

  






In class we began punnett squares.
 

"A" stands for tall and "a" stands for small

                                                                  

This is a punnett square.  As you can see the mother traits(Top) and the father traits(Left) cross together.  When looking at a punnett square you could decide what the genotype and phenotype is .  Phenotype is what the organism will look like on the outside and genotype is what it really looks like from the inside is the percentage to see if the traits are homozygous or heterozygous.  Heterozygous means it is different and homozygous means it is the same.  In addition, homozygous could be label as dominate or recessive.   Dominate and recessive are how traits are label because some traits over power other.  Those traits are dominate.  However, some traits are the opposite.  They are recessive.  For example brown eyes is dominate to blue eyes.  Therefore, brown is dominate and blue eyes are recessive.  Lastly, homozygous and heterozygous are label by percentage.  For example 25%, 50%, 75%, and 100%.In this example above you can see that the scientist cross correctly.  For phenotype is would be 75% tall and 25% short.  For genotype it would be 25% homozygous dominate, 25% homozygous recessive, and 50% heterozygous.  With punnett squares scientist around the world are able to solve more mysteries about genetics.

                                                                                                          By: Whiteknight83