PRE 305 1st Edition Lecture 4Outline of Last Lecture I. Research MethodsA. What is research?B. The scientific methodC. Elements of researchD. Methods of data collectionE. Types of research designsF. Research EthicsOutline of Current Lecture I. Nature and nurtureA. Gene-environment interactionsB. Genetic disordersC. Behavioral geneticsCurrent LectureGene-environment interactions:- Parent/Child Genotype: biological parents pass genes onto children1. Genetic inheritance: one copy of chromosomes from mother and one from father. Father determines the sex chromosome. 2. Genotype: 23 pairs of chromosomes that a person has.3. Phenotype: physical expression of genes (hair color, height, etc.) - Dominant genes: trait that will be evident if one or more copies is inherited. (Brown eyes, brown hair, etc.)- Recessive: trait will be evident only if two copies of the recessive gene are inherited. (Blue eyes, red hair, etc.) Parents will have a recessive trait that they don’t know of. (Parents have brown hair, child has red hair)Genetic disorders- Single gene disorders: can be caused by mutations or by inheriting two copies of a recessive gene. (Tay-Sachs, PKU, cystic fibrosis)- Chromosome disorders: too may or two few of a specific chromosome or breakage of a chromosome. (Down syndrome, Fragile X syndrome)- Disorders with an unidentified genetic basis: genes play a role but no single gene or chromosome determines. (Autism, schizophrenia, depression, alcoholism)- Genetic disorders and the X chromosome: males are more susceptible to genetic disorders arising from genes on the X chromosome because they only have one X chromosome. (hemophilia, red-green colorblindness) Behavioral genetics:- Examining the role of genetics and environment in producing behavior. - Adoption studies: look at biological siblings raised in different environments- Twin studies: look at behavioral similarities to see the influence of genetic inheritance1. Monozygotic (identical) and dizygotic (fraternal)