AP Psychology - Module 14

Behavior Genetics

study of the relative power and limits of genetic and environmental influences on behavior

Environment

every external influence, form the prenatal nutrition to the people and things around us

Chromosomes

- 23 from mom, 23 from dad
- threadlike structures made of DNA molecules that contain the genes

DNA

complex molecule containing the genetic information that makes up the chromosomes

Genes

biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins

Genome

complete instructions for making an organism, consisting of all genetic material in that organism's chromosomes

Identical Twins

- twins who develop form a single fertilized egg that splits in two, creating two genetically identical organisms
- genetically identical
- they don't always have the same number of copies of genes--why one twin may be more at risk of an illness
-if they had separate placenta, one twin may receive better nourishment

Fraternal Twins

- who develop form separate fertilized eggs
- genetically no closer than brothers and sisters, but share fetal environment

Similar and Differences

- identical twins are more similar in extra-version and neuroticism than fraternal twins
- identical twins whose parents treated them alike were not psychologically more alike than identical twins who were treated less similarly

Biological Vs. Adoptive Relatives

- people who grow up together, biologically related or not, do not much resemble one another in personality
- in extraversion and agreeableness, adoptees are more similar to their biological parents than to their adoptive parents
* the environment shared by a family's children has virtually no discernible impact on their personalities

Molecular Genetics

sub field of biology that studies the molecular structure and function of genes

Molecular Genetics

- to find some of the many genes that toegether orchestrate traits such as body weight, sexual orientation, and etc.

Heritability

- proportion of variation among individuals that we can attribute to genes
- may vary,depending on the range of populations and environments studied
- differences among people are attributed to genes
- variation among people; "we can never say what percentage of an individual's personality or intelligence is inherited

Gene-Environment Interaction

- our shared biology enables our developed diversity
- nature vs.nurture

Interact

interplay that occurs when the effect of one factor depends on another factor (environment with heredity)

Epigenetics

- genes can either be active (expressed, as the hot water activated the tea bag) or inactive
-study of environmental influences on gene expression that occur without a DNA change

Epigenetic Mark

- organic methyl molecule attached to part of a DNA strand
- instructs the cell to ignore any gene present in that DNA segment, preventing the DNA from producing coded proteins by that gene