Genes, Environment And Development Flashcards
Species heredity
Genetic endowment members of species having common
Darwin’s arguments
Species has genetic variation
Some genes aid survival more than others
Change that help individuals… Adapt to their environment… Will be passed on to future generations… More frequently than jeans that do not
Natural selection
Evolution
Interaction between genes and environment
Evolutionary psychology
Application of evolutionary theory to understand human thinking/behavior
Sperm cell and ovum
Each contribute 23 chromosomes to the zygote 46 total chromosomes
Chromosomes
Thread like bodies and nucleus of each cell, which contains genes
Sex chromosomes
23rd pair of chromosomes
Male: X&Y chromosomes
Female: X&X chromosomes
Father determines child gender
Meiosis
Cell divides to produce reproductive cells with half of the bodies chromosomes
Crossing over the genetic code
Occurs during meiosis
Pairs of chromosomes lineup before they separate, they cross each other, and parts are exchanged
Identical twins
One fertilize ovum divides to form two genetically identical individuals
Fraternal twins
Two ova release at approximately same time, each is fertilized by a different sperm
Mitosis
Cell divides to produce two identical cells, each containing the same 46 chromosomes
Zygote become multiple cell organisms through mitosis
Genotype
Genetic make up a person inherit
Phenotype
Appearance characteristic/trait that a person has
Gene expression
Activation of particular genes
In particular body cells
At particular times
Single gene pair inheritance
Characteristic influence by only one pair of genes; one from mother one from father
Dominant gene
Will be expressed when present: paired with either recessive or dominant gene
Recessive gene
Will be expressed only in the absence of a dominant gene
Incomplete dominance
Dominant gene incompletely dominates recessive partner gene
Results in blend of two traits
Codominance
Two genes influence a trait such that each is expressed
Sex linked characteristics
Influenced by single genes located on one of the sex chromosomes
Polygenic traits
Influenced by multiple pairs of genes
Often interacting with multiple environmental factors
Mutations
Change in structure or arrangement of one or more genes
Produces new phenotype
Chromosomal abnormalities
Zygote receives too many to few or abnormal chromosomes
Most caused by errors during meiosis (faulty chromosome division)
Main cause of pregnancy loss
Examples of too many chromosomes
Down syndrome: three # 21 chromosomes
Kleinfelter syndrome: XXY(male phenotype), male with one or more extra X chromosomes
Supermale: XYY (male phenotype)
Triple X: XXX (female phenotype)
Hemophilia
Deficiency in blood ability to clot; more common in males than females
Genetic mechanism: sex, linked inheritance, gene on x chromosome
Huntington’s disease
Deterioration of the nervous system in middle age, associated with dementia, jerky movements, personality changes
Genetic mechanism: dominant gene
Phenyl-ketonuria PKU
Lack of enzyme needed to metabolize, phenylalanine in milk and other foods result in acid that attacks the nervous system and causes intellectual disability
Genetic mechanism: recessive gene pair
Sickle cell disease
Blood cells are sickle shaped, stick together, make breathing hard, and cause painful swelling of joints and blood clots; common in African-Americans
Genetic mechanism: recessive gene pair; carriers were protected from malaria
Ways to detect abnormalities prenatally
Ultrasound
Amniocentesis
Chorionic villus sampling
Maternal blood sampling
Pre-implantation genetic diagnosis
Behavioral genetics
Scientific study of the extent to which genetic and environmental differences among people are responsible for differences
Behavioral genetics
Scientific study of the extent to which genetic and environmental differences among people are responsible for differences
Heritability
Proportion of all the variability in a trait within a large sample of people that can be linked to genetic differences among those individuals
Twin studies
Determine whether identical twins reared together are more similar to each other than fraternal twins reared together
Estimating influences: contributions of three factors to individual differences
Genes
Shared environmental experiences
Non-shared environmental experiences
Molecular genetics
An analysis of particular genes and their effects
Involves identification of specific variants of genes that influence particular traits
Helps identify the multiple genes that contribute to polygenic traits
Schizophrenia
Genes contribute substantially
Average concordance for identical twins is 48%
Environment plays a role
Gene environment correlations
Ways that a persons genes and the environment are systematically interrelated
Passive, evocative, active
Molecular genetics
The identification and analysis of particular genes and their effects
Temperament
Tendencies to respond in predictable ways, such as sociability and emotional reactivity
Diathesis stress model
When a combination of high-risk genes and high-risk environment or stressful experiences, triggers a psychological disorder
Differential susceptibility hypothesis
Some peoples jeans, make them more reactive than other people to environmental influences
Orchids
Those of us who are highly susceptible to both good and bad environmental influences
Dandelions
Less environmentally sensitive individuals
Passive gene environment correlations
The jeans they pass on to their children at conception
Evocative gene environment correlations
A child’s genotype also evokes certain kinds of reactions from other people
Active gene environment correlations
Children’s genotypes influence, the kind of environments they seek can create
Genetically informed studies
Correlational studies that show a relationship between some aspect of experience and some aspect of development 
Epigenetic effects
Way in which environmental factors influence, the expression of particular genes and particular cells of the body
DNA methylation
Can be caused by maternal stress during pregnancy. DNA methylation alters the stress response system of the fetus and predisposes the child to difficulties handling stress
Gene therapy
Techniques for altering an individuals genetic make up
