Genetic and Environmental Foundations PDF

Genetic and Environmental Foundations Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Genotype and Phenotype Genotype An individual’s genetic information Phenotype An individual’s directly observable characteristics © szefei/Fotolia...

Genetic and Environmental Foundations Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Genotype and Phenotype Genotype An individual’s genetic information Phenotype An individual’s directly observable characteristics © szefei/Fotolia Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Genetic Foundations Rodlike structures within the Chromosomes cells that store and transmit genetic information Deoxyribonucleic acid, the chemical DNA substance that makes up chromosomes Segment of DNA along the Gene length of the chromosome Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Mitosis and Meiosis Mitosis Meiosis § Process by which § Process by which DNA duplicates gametes (sex cells) itself are formed § Produces new § Halves the number body cells of chromosomes containing the normally present same genetic § Leads to genetic information variability Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Autosomes, Sex Chromosomes, and Sex Cells 22 matching pairs Autosomes of chromosomes Sex 23rd pair of chromosomes chromosomes (XX = female, XY = male) Gametes Sex cells: sperm and ovum Formed when sperm Zygote and ovum unite Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Twins Fraternal/Dizygotic Identical/Monozygotic Result from release Result when a single and fertilization of two zygote separates ova to form two individuals © Blend Images/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Alleles § Two forms of the same gene, one inherited from each parent § homozygous (both alleles are alike) § heterozygous (alleles differ) § Occur at the same place on both chromosomes in a pair Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Dominant–Recessive Inheritance § Only the dominant allele affects children’s phenotypic characteristics § Carriers: § heterozygous (have one recessive allele) § can pass recessive trait to their children § Many serious diseases are product of recessive alleles Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Incomplete Dominance § Both alleles are expressed in the phenotype § Possible results: § combined trait § trait that is intermediate between the two § Example: sickle cell anemia Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. X-Linked Inheritance Figure 2.4 Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. Genomic Imprinting, Mutation, and Polygenic Inheritance § Genomic imprinting: § chemical marker activates one allele in a pair § often temporary; may not occur in all individuals § Mutation: § sudden, permanent change in a segment of DNA § may affect one or two genes, or many § Polygenic inheritance: § characteristics influenced by many genes Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Chromosomal Abnormalities § Down syndrome: caused by problems with 21st chromosome § Sex chromosome abnormalities: § caused by problems with X or Y chromosome § often not recognized until adolescence © Denis Kuvaev/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Reproductive Choices § Genetic counseling § Prenatal diagnosis and fetal medicine § Reproductive technologies © Monkey Business Images/Shutterstock § Adoption Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Reproductive Technologies § Donor insemination § In vitro fertilization § Surrogate motherhood § New technologies © Burlingham/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Genetic Counseling § Helps couples § assess chances of hereditary disorders § choose best course of action in view of risks and family goals § Recommended when § couple has had difficulties bearing children § known genetic problems exist § woman is over 35 Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. Prenatal Diagnostic Methods § Amniocentesis § Chorionic villus sampling § Fetoscopy © PhotographyByMK/Shutterstock § Ultrasound § Maternal blood analysis § Ultrafast magnetic resonance imaging § Preimplantation genetic diagnosis Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Adoption § Trends: § international adoption § adoption of older children § adoption of children with known developmental problems © Vitalinka/Shutterstock § Children typically exhibit some difficulties, but most fare well Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Environmental Contexts for Development § Family § Socioeconomic status and family functioning § Neighborhoods, towns, and cities © Mat Hayward/Fotolia § Cultural context Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Family Influences on Development § Direct influences § Indirect influences: effects of third parties © auremar/Fotolia § Adaptation to changes within and outside the family Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. Socioeconomic Status (SES) § Social status: § years of education § prestige of one’s job and skill it requires § Economic status: income © Yanming Zhang/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Socioeconomic Status and Family Functioning SES is linked to: § timing of marriage and parenthood § family size § values and expectations for children § parents’ education and economic security § communication and discipline styles § investment in children’s cognitive development Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Poverty Who Is Poor? § 46 million Americans (15%) are poor § Those hit hardest are: § parents under age 25 with young children, especially single mothers § older adults who live alone, especially women § children, especially African- American, Native-American, and Hispanic children © gcelebi/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Homelessness § Most homeless families are women with children under age 5 § Many homeless children suffer from: § developmental delays § chronic emotional stress § 25% to 30% of school-age homeless children do not attend school Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Affluence What Are the Risks of Affluence? § Alcohol and drug use § High levels of anxiety and depression § Unavailable parents: § lack of emotional closeness and supervision © Beata Wawrzyniuk/Shutterstock § excessive demands for achievement Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Importance of Regularly Eating Dinner as a Family Figure 2.6 (Adapted from Luthar & Latendresse, 2005.) Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Beyond the Family Benefits of Strong Community Ties § Neighborhoods: resources and social ties that promote development § Towns and cities: mold children’s and adults’ daily lives § Small towns: promote connection and © Petrenko Andriy/Shutterstock participation Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Cultural Context § Cultural values and practices: shape daily life within and outside the family § Subcultures: § cooperative family structures help protect members from harmful effects of poverty § collectivism vs. individualism § Public policies: laws and programs designed to improve current conditions Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Extended Families § Three or more generations living together § More common in many minority cultures § Benefits: § reduce stress of poverty § provide assistance for all generations § create strong family bonds © Hasloo Group Production Studio/Shutterstock § transmit culture to next generation Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Individualistic and Collectivist Societies Individualistic Collectivist § People define § People define themselves as themselves as part separate entities of a group § Independent self § Interdependent self Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Behavioral Genetics How Much Does Heredity Contribute to Behavior? Heritability Estimates § Obtained from kinship studies § Provide an estimate of proportion of individual differences in a trait attributable to heredity § Range from 0 to 1.00 Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Gene–Environment Interaction § Individuals respond differently to same environment because of genetic makeup § Similar responses can result from different gene–environment combinations © atikinka/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Canalization § Tendency of heredity to restrict development of some characteristics to just one or a few outcomes § Ensures development of species-typical skills under many rearing conditions © photomak/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. Gene–Environment Correlation § Passive correlation § Evocative correlation § Active correlation: niche-picking © szefei/Shutterstock Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.  Epigenesis Development results from bidirectional exchanges between heredity and all levels of environment § Genes affect behavior and experiences § Experiences and behavior affect gene expression Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved. The Epigenetic Framework Figure 2.10 (Adapted from Gottlieb, 2007.) Copyright © 2014, 2010, 2007 by Pearson Education, Inc. All Rights Reserved.