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Why are monozygotic twins useful in human heritability studies ? PowerPoint Presentation
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Why are monozygotic twins useful in human heritability studies ?

Why are monozygotic twins useful in human heritability studies ?

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Why are monozygotic twins useful in human heritability studies ?

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  1. For a polygenic trait in a given population, which term represents a measure of the variation in a phenotype due to genetic factors? ✓ 1. Broad-sense heritability 2. Variance 3. Genotype-by-environment interaction 4. Covariance

  2. Why are monozygotic twins useful in human heritability studies? ✓ 1. They are genetically identical 2. They are not used in human heritability studies 3. They are genetically similar in the same way that siblings are; however, they shared the same womb (intrauterine environment) 4. They are raised together in the same environment

  3. Which term describes the degree to which values diverge from the mean? 1. Central tendency ✓ 2. Sample variance 3. Average 4. Standard error of the mean

  4. Which of the following is NOT a component of phenotypic variance? 1. Environmental variance 2. Genotype-by-environment variance 3. Genotypic variance ✓ 4. Selection variance

  5. Narrow-sense heritability refers to 1. the proportion of phenotypic variation that can be attributed to environmental influences 2. how much variation is common to two quantitative traits ✓ 3. the proportion of phenotypic variance due to additive genotypic variance alone 4. traits for which the phenotypes are described by whole numbers

  6. The Final exam The final will be ~85% cumulative, ~15% new material 25-30 multiple choice questions 10-15 fill in the blank 6-8 problems/short answer Cumulative material will only be from Exams 1-4, BUT the questions will NOT be identical New material: Chapter 25, Key terms 14, Homework 10, Lectures 35-37

  7. BIO 304 Lecture 36 “A Critique of the Theory of Evolution,” T.H. Morgan Project Gutenberg Archives

  8. Heritability

  9. Three common misconceptions about heritability 1. Heritability applies to a single individual rather than to differences among individuals. 2. Traits with high heritability cannot be changed. 3. Heritability is a fixed number.

  10. Phenotypic variance

  11. Broad-sense heritability

  12. Narrow-sense heritability

  13. Example The mean and variance of plant petal length in two highly inbred strains of a plant and their progeny are given below. Parental strain 1 has short petals and parental strain 2 has long petals. Calculate the broad sense heritability (H2) of petal length in the F2 plants.