Why do we look similar to but different than our biological siblings?
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Presentation on theme: "Why do we look similar to but different than our biological siblings?"— Presentation transcript:
1 Why do we look similar to but different than our biological siblings? Mendelian GeneticsWhy do we look similar to but different than our biological siblings?
2 Possible Results of Crosses ORORHow is this possible? Can we accurately predict the outcome of crosses?
3 Heredity VocabularyHomozygous = when an organism has two identical alleles for a particular geneEx: GG (both dominant) or gg (both recessive)Heterozygous = when an organism has different alleles for the same geneEx: Gg (one dominant and one recessive)
4 Heredity VocabularyGenotype = genetic makeup (the combination alleles)Phenotypes = physical traitsFor each plant below, list all possible phenotypes and genotypes:Phenotypes: Yellow GreenGenotypes: gg GG or Gg
5 ProbabilityMendel kept getting consistent results for particular crosses64 green48 green and 16 yellow
6 ProbabilityPrinciples of probability can be used to predict the outcomes of genetic crossesProbability= likelihood that a particular event will occurWhat is the probability of the coin landing heads up?
7 Using Segregation to Predict Outcomes G = green allele (dominant)g = yellow allele (recessive)GgGgMeiosis occursGgGgSex cells are produced with one allele each
8 Using Segregation to Predict Outcomes Fertilization occursThere are four possible outcomes:GG (green leaves)Gg (green leaves)gg (yellow leaves)GGGgGggg
9 Using Segregation to Predict Outcomes What is the probability that the offspring will have yellow leaves?What is the probability that the offspring will have green leaves?ggGG, Gg, Gg
10 Punnett SquaresA simple diagram used to predict the outcomes of a genetic crossHow to make a Punnett Square:Write the genotypes of the parentsDetermine the alleles of all possible gametes that each parent could produceDraw a table with enough squares for each gamete of each parentFill the table by combining the gametes’ genotypesDetermine the genotype and phenotype of the offspring.