Chapter 2 Biological and Environmental Foundations

Genetic Foundations Chromosomes – store and transmit genetic information. Genes – segments of DNA located along the chromosomes DNA – substance of which genes and chromosomes are made.

DNA ’ s Ladderlike Structure

Meiosis

Twins Fraternal/Dizogotic Two zygotes, or fertilized ova Identical/Monozygotic One zygote that divides into two individuals

Dominant-Recessive Inheritance

X-Linked Inheritance

Genetic Imprinting and Mutation Imprinting Chemical marker that activates either father ’ s or mother ’ s gene. Often temporary. Mutation Sudden, permanent change in a DNA segment.

Chromosomal Abnormalities Down Syndrome- –results from problems with the 21st chromosome. Sex chromosome Abnormalities- –problems with the X or Y chromosomes.

Chromosomal Abnormalities --Down Syndrome

Prenatal Diagnostic Methods Amniocentesis 羊水诊断 Chorionic villus sampling 绒毛标本检查 Fetoscopy 用胎儿镜观察胎儿 Ultrasound Ｂ超 Maternal Blood Analysis Preimplantation

Fetal Medicine Drugs delivered into uterus Surgery Bone marrow transplants 骨髓移植 Genetic engineering and gene therapy

Reproductive Technologies Donor Insemination In Vitro Fertilization Surrogate Mother 代孕母亲 New Technologies

Adoption and Adjustment

Environmental Contexts for Development Family Socioeconomic Status Neighborhoods Towns and Cities Cultural Context

Family Influences on Development Direct –Two-person relationships Indirect –Third Parties Adapting to Change –Changes from within and outside the family

Socioeconomic Status and Family Functioning Timing of Family Life Cycle Values and Expectations Father ’ s Involvement Communication and Discipline Styles Children ’ s Cognitive Development

Individualist and Collectivist Societies Individualist People think of themselves as separate from other people. Concerned with personal goals. Collectivist People define themselves as part of a group. Concerned with group goals over individual goals.

How Much Does Heredity Contribute to Behavior? Heritability Estimates Portion of individual differences attributable to genetics. Ranges from 0 to Concordance What percent of the time do twins both show a trait? Ranges from 0 to 100%.

Reaction Range

Genetic-Environment Correlation Passive Correlation Evocative Correlation Active Correlation –Niche-picking

Contributions of Environment and Genetics

The Epigenetic 渐成的 Framework