Genetics and Evolution - PSYC 2113

DNA

large, double-helix molecule containing genetic information written in a language using four bases, portions contain genes

gene

section of DNA that codes for creating proteins, come in two forms called alleles

alleles

one of two forms of the same gene, one found on each pair of chromosomes, can be dominant, recessive, or combo of both

homozygous

genotypic configuration where there are either two dominant or two recessive together

heterozygous

genotypic configuration where there is one dominant and one recessive allele together

genotype

allele configuration on chromosomes as either heterozygous or homozygous

Ex. EE, Ee, ee

phenotype

physical/behavioral representation of a gene

law of segregation

organisms have two alleles for each gene and the alleles separate when making sex cells

law of independent assortment

alleles for different genes are passed on to offspring independently of each other

nature vs nurture

idea that nature (genes) are competing against nurture (environment and socialization) for the influence on physical and behavioral traits

ultimate causes

thought to have long-term adaptive functions, refer to genetic or natural causes

proximal causes

influences on behavior that an animal, including humans, experiences within its own life such as learning

PKU

homozygous recessive disorder, good example of nature vs nurture

genetic determinism

philosophy that our genes determine to a large amount of our physical and mental traits, often discounts the influence of experience

epigenetics

study of how environmental experiences contribute to the expression of genes

methyl groups

molecules that act as tags to DNA that affect the expression of genes, repressing transcription

acetyl groups

molecules that loosen DNA allowing transcription

human genome project

massive endeavor to sequence the entire human genome

down syndrome

genetic disorder where a person has an extra 21st chromosome leading to specific physical and mental characteristics

cell-free fetal DNA testing

prenatal test that can detect chromosomal abnormalities in a fetus as early as 10 weeks by testing the mothers blood

carrier testing

genetic testing of parents to determine if they carry recessive alleles for genetic disorder

preimplantation genetic diagnosis

following in vitro fertilization, cell removed at eight-cell stage and tested for disorders and carriers of recessive alleles

pharmacogenomics

method of using genetic testing to determine the best treatments for diseases

single nucleotide polymorphisms

spot on the DNA that has a nucleotide that is only found in a minority of the population, used to identify areas of DNA linked to certain traits

genome wide association studies

large collaborative studies that compare the genomes from thousands of people to find SNPs associated with specific traits

polygenic risk score

method for assessing a persons SNPs to determine their risk for developing psychological and health disorder

genetic engineering

a technique for changing the genetic makeup of an organism by removing genes or inserting genes from other organisms

genetically modified organism

an organism that has had its genome changed

CRISPR-Cas9

technique for genetically modifying organisms that is accurate and relatively inexpensive

gene targeting

method of changing or removing specific genes without adding new genes

behavioral genetics

study of how heritability and genetics influence behavior

heritability

term relating to the influence of genetics and environment on traits

monozygotic twins

identical twins, develop from one sperm and one egg, same DNA

dizygotic twins

fraternal twins, share on average 50% of their genes

concordances

probability of related people developing the same neuropsychiatric disorder

reward deficiency hypothesis

hypothesis that sensation seekers have chronically lower levels of dopamine so they seek out risks and sensations to elevate the nature of dopamine

Charles Darwin

researcher who developed the theory of natural selection to explain the evolution of organisms

theory of natural selection

theory of how organisms evolved based on five basic postulates

eugenics

movement that was motivated to improve the human race

positive eugenics

idea of promoting reproduction in humans with “good” genes

negative eugenics

idea of preventing reproduction in humans with “bad” genes

Immigration Act

act that limited immigration of people from Eastern and Southern Europe and Asia because it was thought these people contained inferior genes

optogenetics

genetic engineering technique where genes for photosensitive receptors are spliced into neurons using viruses

channelrhodopsin

protein that opens Na+ channels when struck by blue light causing an increase in neuron activity

halorhodopsin

protein that opens Cl- channels when struck by yellow/orange light causing an inhibition of neuron activity