CHAPTER 14 MENDEL AND THE GENE IDEA Learning objectives Gregor Mendel s Discoveries 1 Explain how Mendel s particulate mechanism differed from the blending theory of inheritance 2 Define the following terms true breeding hybridization monohybrid cross P generation F1 generation F2 generation 3 List and explain the four components of Mendel s hypothesis that led him to deduce the law of segregation 4 Use a Punnett square to predict the results of a monohybrid cross stating the phenotypic and genotypic ratios of the F2 generation 5 Distinguish between the following pairs of terms dominant and recessive heterozygous and homozygous genotype and phenotype 6 Explain how a testcross can be used to determine if an individual with the dominant phenotype is homozygous or heterozygous 7 Use a Punnett square to predict the results of a dihybrid cross and state the phenotypic and genotypic ratios of the F2 generation 8 State Mendel s law of independent assortment and describe how this law can be explained by the behavior of chromosomes during meiosis 9 Use the rule of multiplication to calculate the probability that a particular F2 individual will be homozygous recessive or dominant 10 Given a Mendelian cross use the rule of addition to calculate the probability that a particular F2 individual will be heterozygous 11 Use the laws of probability to predict from a trihybrid cross between two individuals that are heterozygous for all three traits the expected proportion of the offspring that would be a homozygous dominant for the three traits b heterozygous for all three traits c homozygous recessive for two specific traits and heterozygous for the third 12 Explain why it was important that Mendel used large sample sizes in his studies Extending Mendelian Genetics 13 Give an example of incomplete dominance and explain why it does not support the blending theory of inheritance 14 Explain how phenotypic expression in the heterozygote differs with complete dominance incomplete dominance and co dominance 15 Explain why Tay Sachs is considered recessive at the organismal level and co dominant at the molecular level Learning Objectives for Campbell Reece Biology 8th Edition Pearson Education Inc 1 of 2 16 Explain why genetic dominance does not mean that the dominant allele subdues a recessive allele Illustrate your explanation with the example of round versus wrinkled pea seed shape 17 Explain why dominant alleles are not necessarily more common in a population Illustrate your explanation with an example 18 Describe the inheritance of the ABO blood system and explain why the IA and IB alleles are said to be co dominant 19 Define and give examples of pleiotropy and epistasis 20 Describe a simple model for polygenic inheritance and explain why most polygenic characters are described in quantitative terms 21 Describe how environmental conditions can influence the phenotypic expression of a character Explain what is meant by a norm of reaction 22 Distinguish between the specific and broad interpretations of the terms phenotype and genotype Mendelian Inheritance in Humans 23 Explain why studies of human inheritance are not as easily conducted as Mendel s work with peas 24 Given a simple family pedigree deduce the genotypes for specific family members 25 Explain how a lethal recessive allele can be maintained in a 26 Describe the inheritance and expression of cystic fibrosis and 27 Explain why lethal dominant genes are much rarer than lethal population sickle cell disease recessive genes 28 Give an example of a late acting lethal dominant in humans and explain how it may escape elimination by natural selection 29 Define and give examples of multifactorial disorders in humans 30 Explain how carrier recognition fetal testing and newborn screening can be used in genetic screening and counseling Learning Objectives for Campbell Reece Biology 8th Edition Pearson Education Inc 2 of 2