Chapter 3: Biological Foundations Flashcards
Genotype
Inherited genetic material
Phenotype
Expression of genes
Environment
Defined as everything outside of your genetics
The human genome
Made up of ~20,000 protein coding genes (smaller than estimates); most genes are shared among all living things; genes make up only 1% of the human genome (the rest is non-coding DNA)
Five interactions that build a human
Parent and child genotype; child genotype on parent phenotype; child’s environment and child’s phenotype (two-way interaction); child’s environment on child’s genotype
Parent Genotype affect on Child genotype
Transmission of genetic material from parent to offspring (chromosomes, DNA, genes). Affect development and behavior through protein manufacturing
Mutations
Change in DNA caused by random error or environmental factors; fatal more often than not
Crossing over
Sections of DNA switch chromosomes in gametes. Occurs prior to conception in the sex cells. Two members of a chromosome pair swap DNA sections
Regulator genes
Switch on and off genes; control diversity in genetic expression
Sex Chromosomes
X and Y; XX = female, XY = male, any other combination = intersex.
Sex linked disorders
Genetic mutations that occur only on the X chromosome. More likely to present in males because there is only one copy of the X gene, and no healthy X to replace that mutated data
Alleles
Different forms of genes. Dominant and recessive; homozygous (2 same alleles) and heterozygous (2 different alleles)
Child’s genotype affect on child’s phenotype
Genes affect physical and behavioral characteristics
Endophenotypes
Intermediate phenotypes that mediate pathways between genes and behaviors. Do not involve overt behavior
Polygenic inheritance pattern
many different genes determine the phenotype
PKU example
Example of the genotype affecting the phenotype. If a child is born with PKU and they eat reactive foods they are likely to have issues, but if they avoid the foods then the genetic issue does not present
Child’s Environment affect on child’s phenotype
pre and post natal environments can change how genes are expressed; prenatal tests can screen baby and parents for possibly genetic defects that can be treated
Norm of reaction
All possible gene expressions given a certain environment
Child’s phenotype affect on Child’s environment
The child’s gene expression and behaviors causes their environment to adapt to their needs. Children are active creators of their environment (select surroundings that match their interests/personalities)
Child’s Environment affect on Child’s genotype
Epigenetic mechanisms can alter gene functions despite DNA being “fixed”; can occur before or after gestation
Histone modification
Proteins affected by DNA strand that change expression
Methylation
Silencing of gene expression by blocking transcription in the promoter region of a gene (modified by stress)
Behavioral genetics
Science concerned with how environment and genes influence behavior and development
Heritability
Statistical estimate of how much of a measured variance on a phenotypic trait is attributable to genetic difference; not immutability; not generalizable (can change based on culture and environmental factors)
Multifactoral traits
Traits that are affected by environmental and genetic factors
Genome-wide association studies (GWAS)
Link specific DNA segments with specific traits
Genome-wide complex trait analysis (GCTA)
takes estimates of genetic resemblance across large groups of individuals
Experience-expectant plactisity
the role of general human (species-specific) experience in shaping development. The species has evolved to expect reliable post-natal stimuli to facilitate development
Experience-dependent plasticity
Neural connections are created and reorganized as a result of individual life experiences. Cortical areas can grow for specific training of specific body parts/behaviors
Sensitive periods
Timing where an experience-expectant process is the most sensitive to input/changeF
Frog cell plasticity example
A cell from the belly of a frog can be moved to the mouth area, and will become a mouth cell. Moving the same belly frog cell to the mouth of a salamander will still produce a frog mouth cell. The species does not matter, but the cell can still differentiate depending on location
Cerebral cortex
Grey matter that takes up 80% of the brain and is responsible for higher function. Separated into four lobes
Hippocampus
Involved in memory and learning
Amygdala
Involved in arousal and four Fs (fight flight feed fuck)
Basal ganglia
Involved in voluntary movements, decision making, learning and memory
Neurons
Cells that carry electric potential and can communicate with each other; more than 100 billion in the brain
Pyramidal cells
Triangle shape, very long, transmit info between regions
Marian Diamond
Very famous neuroscientist
Glial cells
Support cells that assist functions in the axon/neuron; creates myelin sheaths, cleans the synaptic space, and can lead to increased IQ
Synaptic pruning
The brain gets rid of neurons over development, and cortical mass decreases. (mass loss occurs in the cortex and basal ganglia, but mass gain occurs in the hippocampus)
Neurogenesis
Proliferation of neurons through cell division
Spines
Formations on dendrites that increase connection capacity
Plasticity
Capacity of the brain to be changed by experience (decreased by myelination)
Synaptogenesis
Process where neurons form synapses with other neurons
Synapse elimination
Removal of unused/less active connections/synapses
Amblyopia
“lazy” eye, brain ignored the lazy eye and the dominant eye takes over, Can be corrected with eyepatches
Effect of enriching environments
Can affect neuronal populations and cause more connections between neurons
Hubel and Wiesel kitten experiment
Sewed one eye of the kitten shut; found that the dominant eye will take over and discovered the sensitive period of visual development (in kitten)
