Thursday, September 18, 2008

Dragon-Punnett Square Lab

Meiosis division results in  daughter cells that are not identical and the resulting offspring can manifest different phenotype. Meiosis creates genetic diversity. During fertilization depending on  cell makeup the offspring can vary from the parent because of a recessive gene. In the diagram of the dragons genetic makeup the letters can match up but if there is a recessive trait it will show up in the phenotype although the genotype is similar. How the alleles interact affects the appearance of the offspring. The alleles constitute the genotype and the genotype expresses the phenotype.  


The Punnett square was developed by R C Punnett an English Biologist. It is used to help determine ways that alleles combine. A cell carries two alleles for each trait. One from the mother  and another from the father. Each has two alleles for each trait. A homozygote has two identical alleles and a hetrozygote has two different alleles for a gene.  A dominant allele is shown as uppercase letters and the recessive in lowercase letters. Homozygous dominant is a genotype that is shown in the square as LL, homozygous receptive is ll, and hetrozygous is Ll. Dihybrid cross is when two traits are being considered and monohybrid is when one is being considered.

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