GCD 3022 1st Edition Final Exam Study Guide Lectures 1 12 Chapter 2 January 26 30 Why did Mendel s work refute the idea of blending inheritance Provide an example that supports your answer Mendel s work refuted the blended inheritance because his experiments showed that the offspring of any given generation will have one of the parental phenotypes not a new phenotype For example a red flower and white flower will produce offspring with either red or white flowers no pink flowers Describe the difference between genotype and phenotype Can two individuals have the same phenotype and different genotypes The genotype of an individual is that individual s genetic makeup alleles while the phenotype is how those alleles appear physically It is possible to have different genotypes and the same phenotype between two individuals because in a dominant recessive inheritance pattern any individual with a dominant allele will express the dominant phenotype whether that individual is homozygous dominant or heterozygous An example of this would be if two purple flowers had different genotypes where one was PP and the other was Pp A pea plant that is heterozygous Yy for seed color in which yellow Y is dominant to green y is allowed to self fertilize Predict the genotypes and phenotypes of the resulting offspring The offspring will be YY Yy and yy with YY and Yy being the yellow offspring and yy being green These genotypes can be predicted using a Punnett square When do you use the binomial expansion equation vs the product rule to calculate probability The binomial expansion equation is used when the order of events does not matter ex out of 7 plants 3 are tall and 4 are dwarf The product rule is used to calculate events that are in order ex the first plant is tall the second is dwarf and the third is dwarf These rules can also be used in combination with each other What does the term true breeding mean True breeding refers to an individual that will produce offspring with the same phenotype for many generations in other words a true breeding individual is homozygous for the desired trait Chapters 3 and 4 February 2 6 With regard to flower color in sweet peas explain how complementation can occur when two different white flowered strains are crossed to produce purple flowered offspring focus on the concept of loss of function vs functional alleles Complementation refers to the inactivation or loss of function of one of the two alleles for a trait In this case the allele for white flowers undergoes the loss of function mutation and this results in the expression of only the functional purple flower allele Why are the products of mitosis genetically identical and the products of meiosis not Mitosis is the replication of somatic autosomal cells which means that the genetic material of these cells is identical Meiosis is the process of dividing up chromosomes into gametes which may result in genetically different cells depending on the genotype of the parent if the parent is homozygous for a gene then all gametes will carry the same allele Define dominance incomplete dominance codominance and overdominance Dominance simple Mendelian genetics One allele is dominant and one is recessive Any individual with at least one dominant allele will express the dominant phenotype for that trait Incomplete dominance occurs when one dominant allele is not sufficient to produce the dominant phenotype The result is an intermediate or blended phenotype Ex flower that is heterozygous for red white color would display a pink phenotype Codominance in heterozygotes both alleles exert their effect on the phenotype Overdominance heterozygotes have a phenotype that is superior to homozygous phenotypes Define the following concepts in terms of the amount of DNA each possesses relative to an unreplicated chromosome Homolog has the same amount of genetic information as a chromosome A homologous pair aka chromosome may not be genetically identical Each homolog will have the same number of genes and be relatively the same size but may have different alleles Sister chromatid has the same amount of genetic information as a chromosome A pair of sister chromatids are genetically identical because they are replicated Bivalent a pair of pair of sister chromatids 4 sister chromatids or 2 chromosomes Formed during prophase 1 of mitosis The formation of bivalents can also lead to recombination between chromosomes What does it mean if a trait is found to be 80 penetrant A gene that is 80 penetrant means that in 80 of cases 50 of the allele is sufficient for the desired phenotype In other words 20 of people who carry this allele will not express the desired phenotype Chapter 5 February 9 13 Petunias have a trait that confers either a normal or pale petal color A true breeding pale plant was pollinated by a true breeding normal plant All of the F1 generation had pale petals The F1 offspring were then pollinated by a true breeding normal plant All of the F2 generation had pale petals Explain this pattern of inheritance Since the male plant is the one that does the pollinating and the offspring of every generation have pale petals regardless of the father s phenotype it can be concluded that this is a pattern of maternal inheritance That means that only the mother s phenotype matters and in each generation the mother has a pale color phenotype You are analyzing a gene and find that although the two copies of the gene in both the female and male parents appear wild type by sequence analysis only the maternal allele is expressed in offspring What pattern of inheritance explains this scenario Genomic imprinting Genomic imprinting is defined as the expression of alleles from only the mother or the father If an allele is imprinted then it is the one that is expressed In this case the mother s allele for this trait is imprinted so the father s allele is not expressed in the offspring What is the main difference between maternal effect and maternal inheritance Maternal effect means that the phenotype of the offspring is dependent on the genotype of the mother Maternal inheritance means that the phenotype of the offspring is dependent on the phenotype of the mother Chapters 6 and 8 February 16 20 When applying a Chi Square analysis in a linkage problem explain why an independent assortment hypothesis is used It is impossible to calculate the expected distance between linked genes but it is possible to calculate the expected ratio of phenotypes based