I have been using Punnett squares to help me learn about dominant and recessive traits. A Punnett square is a chart you can use to identify what dominant or recessive traits you may have inherited from your parents. You can use capital letters to represent dominant traits and lower case letters to represent recessive traits. So, if there is a capital letter in front of a lower case letter, then the dominant trait will mask over the recessive trait, this is called a heterozygous dominant genotype. (Heterozygous is pair of genes where one is dominant and one is recessive—the dominant one shows.)


I did a project using two popsicle sticks representing chromosomes (chromosomes are the part of every cell that caries genetic information). On them there were some capital and lower case letters on them representing genes. (Genes carry the traits transferred from the parent to the offspring, for example eye color and hair texture.)

I chose one for a male parent and another for a female parent and lined them up next to each other to see witch genotype their offspring would have (genotypes show what alleles you inherit for each trait).

The letters that were capital masked the lower case alleles (Alleles are one of a pair of genes that appear on a particular location on a particular chromosome—some are dominant and some are recessive. Dominant means to be in control, so the dominant allele masks the recessive one. To show a recessive trait, both alleles must be recessive.)

Then, I recorded the information of each gene. Some of the pairs of genes were Homozygous. (Homozygous means you’ve got a pair of matching Alleles—either both dominant or both recessive.)

There were a lot of heterozygous genotypes. There was a chart on the paper for my genetics activity where I was marking the information I got. Then I put the genotypes next to each other to show what phenotype my bug had for each gene. (Phenotype is an organism’s physical appearance and behavior) The capital letters were Dominant and the lower cases ones were recessive. So, for example if the chromosomes lined up with the eye color gene as Ee, that meant the insect would have the dominant eye color of blue. If the body section gene was Bb, that meant the insect would have 3 marshmallow body segments. Three pairs of legs had the genotype of LL.


Here is my little genetic experiment. I call her Tassie. The only recessive trait she has is tt, for 1 pair of wings.


https://www.vocabulary.com/ helped me with some definitions for this post.


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