1. Chapter 2: Genetic Bases of Child Development

2. Chapter 2: Genetic Bases of Child Development Chapter 2 has two modules: Module 2.1 Mechanisms of Heredity Module 2.2 Heredity, Environment, and Development

3. Mechanisms of Heredity The Biology of Heredity Single Gene Inheritance Genetic Disorders

4. Module 2.1 Mechanisms of Heredity What are chromosomes and genes? What are dominant and recessive traits? How are they inherited? What disorders are inherited? Which are caused by too many or too few chromosomes? Module 2.2 Heredity, Environment, and Development

5. The Biology of Heredity A Quick Review Cell Sperm Egg Chromosome DNA

6. The Biology of Heredity Chromosomes Autosomes Sex chromosomes Gene Genotype Phenotype

7. Single Gene Inheritance Genes come in different forms known as alleles Homozygous or heterozygous Dominant or recessive allele Incomplete dominance Think about these terms as you look at the next slide.

8. Sickle Cell Trait: An Example of Incomplete Dominance Do you see why? Individuals with one dominant and one recessive allele have the SC trait.

9. Genetic Disorders: Inherited Often triggered through inheritance of two recessive alleles Inherited disorders (Table 2.2)

10. Genetic Disorders: Chromosomes Too many, too few, or damaged chromosomes Abnormal chromosome numbers (Table 2.3)

11. Heredity, Environment, and Development Behavioral Genetics Paths From Genes to Behavior

12. Module 2.1 Mechanisms of Heredity Module 2.2 Heredity, Environment, and Development What methods do scientists use to study the impact of heredity and environment on children’s development? How do heredity and environment work together to influence child development?

13. Behavioral Genetics Behavioral genetics: inheritance of behavioral and psychological traits Polygenic inheritance Let’s look at an example on the next slide.

14. An Example of Polygenic Inheritance Phenotypes distribute with extremes at both ends Combined activities of many separate genes

15. Methods of Studying Behavioral Genetics Twin studies and adoption studies Compare identical and fraternal twins or adoptive and biological siblings to measure the influence of heredity If identical twins are more alike than fraternal twins, this implicates heredity.

16. Behavioral Genetics True or false? Cognitive abilities, psychological disorders, substance abuse, and personality are all affected by heredity.

17. Behavioral Genetics Plomin’s Adoption Studies Child intelligence correlated more strongly with biological mother’s intelligence than adoptive mother’s intelligence Hereditary and environmental contributions to intelligence proposed

18. And so… Heredity and environment interact dynamically throughout development.

19. Paths From Genes to Behavior Behavioral consequences of genetic instructions Depend on environment in which those instructions develop Reaction range Heritability coefficient

20. Paths From Genes to Behavior Heredity and environment interact dynamically throughout development Genes can influence the kind of environment to which a child is exposed Environmental influences typically make children within the same family different What are the paths?

21. Paths From Genes to Behavior Epigenesis Continuous interplay between gene and multiple levels of environment drives development Heritability coefficient

22. Paths From Genes to Behavior Niche-picking Deliberately seeking environments that fit one’s heredity Take a minute to think about environments you sought out as a child. What was your niche?

23. 2.2 Paths From Genes to Behavior Why aren’t all children in the same family identical? Environmental influences Non-shared environmental influences Child influences

24. The Relation Between Genes and Environment