Mendel’s Laws Law of Segregation -Genes are found in pairs -The genes that are given to the offspring from the parents are randomly given -There is a 50% chance of the offspring receiving either of the parents alleles

Mendel’s Laws Brown Vs. Black Flies Red Brown Eyes Law of Independent Assortment -Genes that are responsible for traits do not affect each other and are not related to each other -The gene that codes for pea color and the gene that codes for seed shape are not dependent on each other

Punnett Squares (Female) (Male) -A Punnett Square is a way to predict the genotype and phenotype of an offspring -Punnett Squares are a probability, not an absolute certainty -A monohybrid Punnett Square analyzes the probability of a single gene (ie. color, size, shape, etc) (Female) (Male)

Punnett Squares (Female) (Male) -in the example above, each “side” represents the alleles either a male or female can give to the offspring -the probabilities of the above are based on quarters (or ¼), thus, there is a 75% chance the offspring will have green pods, and a 25% chance of yellow pods

Punnett Squares -To solve a Punnett Square, parental alleles go on the left and the top, and the alleles are then placed in the appropriate box

Punnett Squares (Female) (Male) -the probabilities of the above are based on quarters (or ¼), thus, there is a 75% chance the offspring will have green pods, and a 25% chance of yellow pods -there is a 25% chance the offspring will be homozygous dominant, a 50% chance the offspring will be heterozygous, and a 25% chance the offspring will be homozygous recessive

Punnett Squares Questions: 1. There is a plant that either has purple or white flowers. If white flowers are recessive to purple flowers, what will the parents in the Punnett Square below look like? 2. What are the chances that the offspring will have purple flowers? What are the chances that the offspring will have white flowers? 3. What are the chances that the offspring will be homozygous dominant? What about heterozygous? What about homozygous recessive?