Biology and Behavior Flashcards
genome
complete set of an organisms genes
mapped completely by researchers
genotype
inherited genetic material
phenotype
observable expression of genotype, both environment and behavior
environment
every aspect of individuals and their surroundings except genes
chromosomes
molecules of DNA that transmit genetic information
DNA (deoxyribonucleic acid)
carries all biochemical instructions involved in the formation/function of an organism
46 chromosomes, 23 pairs, in nucleus of each cell
random assortment
chromosomes at conception, ensures variation
crossing over
gametes divide, chromosomes may swap DNA
sex chromosomes
X/Y, determine sex a birth, only sperm cary Y chromosome
endophenotype
- intermediate phenotype (brain/nervous system) that do not involve overt behavior
regulator genes
control activity in other genes, often a chain reaction,, results in genetic diversity!
alleles
two or more different forms of a gene
Mendelian inheritance pattern
either dominant or recessive
homozygous or heterozygous
why are men more likely to experience sex-linked genetic disorders?
Y chromosome, so if they have a recessive X chromosome there is nothing to “cancel” it out
polygenic inheritance
inheritance pattern in which traits are governed by more than one gene
histone acetylation
promotes gene activity
histone methylation
inhibits genetic activity
phenylketonuria (PKU)
recessive gene on chromosome 12, cannot digest phenylalanine/aspartame, can cause impaired brain development, but if kept away, there is no problem
carrier genetic testing
used to determine if prospective parents are carriers of certain genetic disorders
ex. Jewish and Tay Sachs or African-American and sickle cell
prenatal testing
used to assess fetus risks (maternal blood, fetal DNA, placenta, amniotic fluid)
aneuploidy
missing or extra chromosome
newborn screening
pinprick to heel, tests for 30-50 genetic disorders
behavior genetics
studies how variations in behavior development results from genetic and environmental factors
assumes all behavioral traits are at least somewhat heritable
assumes reared together more similar than reared apart
types of behavioral genetics studies
family study, twin study, adoption study
heritability
statistical estimate, proportion of measured variance in a given train that is attributable to genetic differences
common to find 50% in variance due to genetic differences
only applies to certain populations in a particular environment
genetic disorder patterns
dominant/recessive (sickle cell)
sex-linked (color blindness)
polygenic (cancer)
chromosomal (Down syndrome)
gene anomalies (Williams syndrome)
unidentified genetic basis (ASD)
gene/environment correlation
certain genes go with certain environments
ex. Niche-picking – active correlation
ex. parents like to read..have books in the home…child likes to read – passive correlation
evocative gene/environment correlation
child evokes a reaction, that reaction changes behavior
gene/environment interaction
effect of one variable depends on the levels of the other variable
neuron
specialized cells that send and receive messages between the brain and all parts of the body
cell body
contains basic biological material to keep neuron functioning
dendrites
fibers that receive input from other cells and conduct it toward the cell body
axon
a fiber that conducts electrical signals away from the cell body to other neurons
synapse
junction between axon nd dendrite branches of another neuron (hundreds of trillions in the human brain)
gilal cells
form the myelin sheath, increase efficiency, protection and regeneration of neurons
cerebral cortex
“gray matter” of brain, 4 distinct lobes, folds/fissures increase surface area
occipital lobe
processing visual information
temporal lobe
speech/language, processing emotion and auditory information
parietal lobe
spatial reasoning, integration of information from sensory modalities
frontal lobe
cognition control, working memory, planning, decision making, inhibitory control
association areas
lie between major sensory/motor areas, great deal of interactivity
cerebral hemispheres
two halves of the cortex, correspond with opposite side of the body
corpus callosum
dense tract of connective nerves between the two brain hemispheres
cerebral lateralization
specialization of the hemispheres for different modes of processing
neurogenesis
proliferation of neurons through cell division, begins 42 days after conception
arborization
formation of new dentritic trees/branches
spines
increase dendrites capacity to form connections with other neurons
mylenation
formation of myelin sheath around some axons become “white matter”
synaptogenesis
neurons form synapses with other neurons, results in trillions of connections
synaptic pruning
synapses that are rarely activated are eliminated
primarily through puberty into adulthood
plasticity
capacity of the brain to be affected by experience, allows less information to be encoded into genes
children’s brains are more plastic than adults
experience-expectant plasticity
normal wiring of the brain due to species-typical experiences
ex. Hubel and Wiesel kitten eye experiment
experience-dependant plasticity
neural connections are created and reorganized throughout life as a function of the individual’s experiences
richer the environment, more connections
secular trends
marked changes in physical development that have occurred over generations
ex. height, menstration
benefits of breatfeeding
free of bacteria, free, contains mother’s antibodies, skin-to-skin
food neophobia
unwillingness to eat new foods
vaccine benefits
eradication of some deadly childhood diseases
some hesitant due to false research on autism and MMR vaccine
