Genetics Lab

Example of a Punnet square for 2 heterozygous genotypes

NOTE - there might be some missing images...for

some reason my computer and adding images to this blog just wasn't working...I lost my whole blog post at one time and had to redo it all

I, personally, found Chapter 20, "Patterns of Genetic Inheritance", to be the most interesting so far. I can remember enjoying this part of biology back in 9th grade, but that was a good fifteen years ago. Genetics basically is what defines who we are. Our parents, our grandparents, and ancestors before them have passed down their genetic information to us to help make us who we are. It can be anything from the color of our eyes, to, unfortunately, being more susceptible to a disease. Once again, I couldn't get my computer to cooperate with copying the whole screen, so I again have images from my digital camera.l'd like to define some basic genetic terms.

final screen from fruit fly punnett square

Both parents were heterozygous dominant (meaning they carried one dominant and one recessive gene which presents as a dominant trait)

Genotype is the genes that an individual has. The following Punnet square shows the genotype of a pollen (Bb), crossing with a pistil (also Bb)

Phenotype is the visual characteristic that an individual has. Here, I am going to seize the opportunity of showing off my daughter by using the illustration that red hair is a phenotype.

An allele is the alternative forms of a gene that have the same position on a pair of chromosomes and affect the same trait.

A cross is what you get when you combine the genes of both parents and come up with the characteristics of the offspring. (final screen of dragon genetics...all genes were matched up...I actually had a hard time matching the color until I realized you could look up what the genotype was supposed to be)

An example of genotype in this lab would be the gene for color 2 Bb, and the phenotype would be the dragon's blue skin.

A dominant allele is expressed by the use of a capital letter, and has a higher chance of being passed on as does a recessive. For example, the genotypes EE, and Ee would both show the dominant trait.

A recessive allele is expressed by the use of a lowercase letter, and when mixed with a dominant, the dominant trait will show. Only the genotype ee would show the recessive trait.

Once again, genetics makes up most of who we are. We inherit many things from our ancestors from red hair to anemia.

http://users.adelphia.net/~lubehawk/BioHELP!/psques3b.jpg