Biology & Behavior (CH 3) Flashcards
1
Q
What are the 3 key elements of Nature vs Nurture model?
A
- Genotype
- Phenotype
- Environment
2
Q
What are the 5 Components of Nature vs Nurture model?
A
- Parent’s genotype-Child’s genotype
- Child’s phenotype-Child’s genotype
- Child’s environment-Child’s phenotype
- Child’s phenotype-Child’s environment
- Child’s environment- Child’s genotype
3
Q
What is Parent’s genotype-Child’s genotype all about?
A
- Transmission of genetic offspring
- Nucleus of every cell=chromosomes= made of 2 twisted strands of DNA= instructions for formation/ functioning
- Packed in genes (sections of chromosomes)= code for the production of particular proteins
- Genes effect development ONLY through the manufacture of proteins
- 2% of genes make up human genome vs 98% of genome plays supporting role in influencing genetic transmission by regulating activity of protein-coding genes
4
Q
What’s the difference between Sex Chromosomes & Normal Chromosomes?
A
- Humans have total of 46 chromosomes= 23 pairs
- Sex chromosomes do not have the same amount but each is the same size & shape
5
Q
How is Sex Determined?
A
- Females have 2 large X chromosomes vs males having X chromosomes w/ smaller Y chromosome
- ALWAYS father who determines sex
- X bearing chromosome fertilizes egg= female
- Y bearing chromosome fertilizes egg= male
- Gene w/ Y chromosome= encodes protein that triggers preantal formation of testes (hormone testosterone)
6
Q
How may Diversity & Individuality come across biologically?
A
- Changes that occur in a section of DNA= occur in germ cells are passed off to offspring
- Mutations/ natural selection
- Random assortment of chromosomes during formation of egg & sperm= 23 pairs of shuffled chromosomes= odds are 0 (except twins) to have same genotype
- Crossing over= Gametes divide, 2 members of a pair of chromosomes swap sections of DNA
7
Q
What is Child’s phenotype-Child’s genotype?
A
- Endophentypes= Intermediate phenotypes
- Mediate pathways between gene & behavior
8
Q
What are Gene Expressions in Developmental Changes?
A
- Switching genes on & off= controlled by regulator genes
- When one gene turns off another may turn on & vise versa
- Regular genes can function multiple times in multiple places during development= results in enormous diversity in gene expression
9
Q
How can External Factors affect Gene Expressions?
A
-Early visual experience necessary for normal development in visual system causes switching on in certain genes in the visual cortex
10
Q
What are the Dominant Patterns in Gene Expression?
A
- Genes have 2 or more different forms alleles= influences same trait/ characteristic but contribute to different developmental outcomes
- Dominant-Recessive Pattern= Can be 2 of the Same allele= Homozygous vs 2 different alleles= Heterozygous
- Polygenetic Inheritance= traits that are governed by more than one gene (shyness, aggression, language learning)
11
Q
What is Child’s Enviornment-Child’s Phenotype?
A
-Given phenotype will develop differently in different enviornments= range of outcomes would be possible
12
Q
What is an example of Genotype/ Enviornment intereactions?
A
- Phenlketonuria (PKU)= defective chromosome 12
- Can’t metabolize phenaline (amino acid in red meats, artificial sweetners)= accumulates in blood stream & causes brain impairment
13
Q
What are the Prental Contributions to a Child’s Enviornment?
A
- Highly salient & most important part of child’s enviornment= Relationship w/ parents
- Gene Enviornment Correlations= enviornment that parents provide is due to parent’s own genetic makeup
14
Q
What is Child’s phenotype- Child’s enviornment?
A
- Restates Active Child Theme=Child as a source of their own development= experiencing/ making different enviornments by the virture of their own behavior& interests
- Actively selecting enviornment they wanna be in
15
Q
What is Child’s environment- Child’s Genotype?
A
- Epigenetics= how known structure of DNA is fixed but certain epigenetic mechs that are mediated by enviornment can alter functioning of genes & create stable changes in expression (some can be passed on)
- Stable change in gene expression bc of environment is process of Methyltion= silencing gene expression
16
Q
What is Behavioral Genetics?
A
- How variation in behavior development results from interactions of gene & enviornmental factors
- All behavioral traits= inheritable & influenced by hereditary factors
- Intelligence, mood, agression,= polygentic & multifactorial= affected by host of both enviornmental factors & genetic
17
Q
What are the Behavioral Genetic research designs?
A
- Twin study (DZ vs MZ)
- Equal Environment Assumption
- Adoption study/ Adoptive twins (reared apart vs together)
18
Q
What is the Family Study of Inheritance?
A
- Measures Intelligence
- Both genetic environment & environmental influences
- MZ twins have more similar IQ that DZ twins
- As twins get older, degree of variance in IQ is accounted by genetic similarity increases
19
Q
What is Heritability?
A
- Statistical estimate of how much of the measured variance on a trait among individuals in a particular environment/ population is attributable to genetic differences among those individuals
- Estimating heritability automatically estimates the proportion of variance not attributable to genes
20
Q
What did the Genome Wide Association Studies (GWAS) discover?
A
- Revealed genetic effects are cumulative
- Takes combo of genes each w/ a small effect to render heritable trait
- Different developmental forces may be operating in poor vs affluent environments
21
Q
What does Genome Wide Complex Trait Analysis (GCTA) do?
A
- Takes advantage of actual genetic resemblance across large groups of individuals
- Makes it possible to tease apart aspects of gene & environment that are confounded within families
- Allows researchers to determine whether the same genes are implicated in measures of particular trait across development
22
Q
What are the Environmental Effects of Behavioral Genetics?
A
- Shared environment inferred positive emotion in MZ & DZ twins who are reared together have similar degree to showing pleasure
- Shared environment effects disorders that clear genetic component= likelihood that a sibling will be diagnosed w/ ASD
- Birth order= different experiences (mom always loved you best syndrome)
23
Q
What are the different types of Neurons & their Functions?
A
- There’s more than 100 bill neurons= gray matter in brain
- Sending & receiving messages between brain/ itself & all parts of body
- Neurons consist of Soma, Dendrites, Axon
- Motor neurons sends info from brain to muscles & glands
- Interneurons= Intermediaries between motor & sensory neurons
24
Q
What does the Soma of a Neuron do?
A
- Body of the cell
- Biological matter that keeps neurons functioning
25
What do the Dendrites of Neuron do?
-Fibers that receive input from other cells & conduct it to soma by electrical pulses
26
What does the Axon of Neuron do?
- Fiber that conducts electrical signals away from cell body & other neurons
- Communication via synapse= electrical & chemical messages
27
What are Glial Cells?
- Form the Myelin Sheath around axons= insulation & increases speed of info transmission
- Promote brain health= Function as neural system & progenitor cells during development
- When brain is injured, certain type of glial cells react by increasing in #'s= protects brain & aiding in regeneration
28
What does the Cerebral Cortex do?
- 80% of human brain
| - Plays primary role in hearing, reading, writing, doing math, feeling compassion, communication w/ others
29
What is the role of the Occipital Lobe?
-Involved in processing visual info
30
What is the role of the Temporal Lobe?
-Memory, visual recognition, speech/language processing of emotion and auditory info
31
What is the role of the Parietal Lobe?
- Spatial processing, integration of info info from different sensory modalities
- Integrating sensory input w. info stored in memory & internal states
32
What is the role of the Frontal Lobe?
- "Executive"
| - Cognitive control, working memory, planning, decision making, inhibitory control
33
What happens to info that come from multiple sensory systems?
-Processed & integrated in association areas= lie in between sensor & motor areas
34
What are the areas that grow the most as a child develops?
- Prefrontal, parietal, temportal corticies
| - Sensory & motor areas are expanded less during evolution
35
What is Cerebral Laterization?
- 2 separate halves= Cerebral Hemispheres which communicates via Corpus Callosum (dense tract of nerve fibers that connects both halves)
- Each hemisphere has specialized modes of processing
36
What is Neurogenesis?
- Proliferation of neurons through cell division= begins 42 days post conception & virtually complete halfway through gestation
- Occurs in the hippocampus
- Can be inhibited by stress
- Neurogenesis later in life= adaptive bc it increases under rewarding conditions & decreases in threatening environments
37
How do Neurons move to develop in different parts of the brain?
-Require guides (Radial Glial cells) which provides scaffolding for neurons to correctly find their destination
38
What is the Process of Neuron Development?
- First it grows axons then bush of dendrites
- Axons elongate as they grow to targets
- Arborization= increases capacity of dendrites to form connections w/ other neurons (after birth)
- Myelination= formation of the insulating myelin sheath around axon. Begins before birth & continues to early adulthood
- Mylated portions= white matter, lie below gray matter (cell bodies) at surface of cortex
39
What is White matter?
-Mylated portions of axons
40
What is Gray Matter?
-Cell bodies
41
What is Synaptogenesis?
- Each neuron forms synapses w/ thousands of others= formation of trillions connections
- Begins prenatally & proceeds rapidly before birth & sometime afterwards
- Timing & rate of synapse production vary for different cortical areas
- Contributes developmental timing of the onset of various abilities & behaviors
42
What is the result of the explosive generation of synapses & neurons during Synaptogenesis?
- Surplus= excess of connections between different parts of the brain= Synesthesia ( blends different sensory inputs)
- Synaptic pruning beings to take its course
43
What is Synaptic Pruning?
- Synaptic elimination
- Different times for different areas of the brain
- S.P in visual cortex begins 1st year of life & continues until 10 yrs while prefrontal area is slower
- Gray matter proceeds rapidly, peaks around puberty & declines when some of it is replaced by white matter
- Last area to mature is Dorsolateral Prefrontal Cortex
44
What is the role of the Dorsolateral Prefrontal Cortex?
- Regulates attention, controls impulses foresees consequences, sets priorities
- Other executive functions
- Does not reach adult dimensions until after 20 yrs old w/ Synaptic pruning at 30s
45
What is the Importance of Experience?
- Central role of use it or lose it= neural Darwinism/ Neurons that fire together stay together
- Capacity of the brain can be molded/ changed by experience= less info needs to be encoded in genes
46
What is Experience- Expectant Processes?
- Experience Dependent plasticity plays role of general human experience in shaping brain development
- Normal wiring of the brain is resulted from experience that have been present through human evolution
- Brain can expect input from visual stimulation, voices & other sounds, movement & manipulation= fine-tune's its circuitry
47
What are the Pros for Experience-Expectant Processes?
- Fewer genes need to be dedicated to normal development
- Brain is better able to recover from injury in certain areas of the brain bc other brain areas take over
- Brain areas can atleast be partially reorganized to serve another function= Cross Modal Reorganization?
48
What are the Con's to Experience-Expectant Processes?
- Accompanied by vulneralbility
| - If experience that developing brain is "expecting" does not occur, development may be compromised
49
What is Cross-Modal Reorganization?
- When a function that was meant to be for "expecting" stimuli are changed to be apart of a different function
- People who are blind/ have early cataracts, the auditory function takes over the areas that are for the visual system
50
What are the Sensitive Periods in Experience-Expectant Plasticity?
-Window of time where brain is most sensitive to particular kinds of external stimuli, neural organization that occurs or not during this period cannot be reversed
51
What is Experience-Dependent Processes?
- Brain is sculped by Idiosyncratic Experience= Experience Dependent Plasticity
- Neural connections are created/ reorganized constantly throughout life as a function of an individual's experiences
- EX; particular body parts are trained more than others= musicians who played wind instruments had thicker lip-related cortical areas
52
What's up with children with Brain-Damage and their Recovery?
- Have greater chance of recovering from lost functions that adults bc other areas of immature brain take over those lost functions
- Worst time to suffer brain damage is during prenatal development & 1 yr after birth when neurogenesis is occurring & basic brain structures are being formed
- Higher chance of recovery if have brain damage during early childhood (synapse regeneration & pruning & plasticity is at its highest
53
What about Atypical Brain wiring?
- Observed in developmental disorders= brain areas show unusual patterns of connections
- ASD= connections between brain areas that diverge from typical developmental path= categorized by over & under abundance of connections relative to neurotypical brain
- Subcortical are overconnected vs Cortical regions are underconnected
- Wiring abnormalities occur in schizophrenia= gene produces excessive synaptic pruning
54
Human growth?
- Grows & develops for 20% of human life span
- We become 15-20 times heavier & 3 times taller between birth & 20 yrs
- Growth is uneven over time, steep slope on growth curve= rapid growth that usually occurs during the first 2 years of adolescence
55
How do boys & girls grow?
- Both are essentially equal in weight & height until 10-12 yrs
- Boys experience growth spurt 2 years after girls
- Full height achieved on average is 15.5 yrs for girls vs 17.5 for boys
- Proportion in body fat is highest in infancy & then decreases at 6-8 yrs
- Girls body composition increases due to menstration
56
What role does Variability play in the growing body?
- Genes affect growth & sexual maturity influencing the production of hormones
- Secular trends= marked changes in physical level has occurred over generations (adults being several inches taller than grandparents)
- Combo of genetic & environment= involved in failure to thrive (infants become malnourished & fail to grow)
57
What are the effects of Breast Feeding?
- Naturally free of bacteria, strengthens infant's immune system, contains mom's antibodies, good for mothers health (low risk of cancer & type 2 diabetes)
- Fatty acids in the milk= positive effect on cognitive development= based on child's genotype-environment interaction
58
What are the tastes that infants can come across?
- Sweet, umami (savory), bitter, sour, salty
| - Child doesn't come across salty until 4 months old
59
Where does Food Preferences come from?
- Preference for sweet things may have an evolutionary origin bc poisonous foods were bitter/sour
- Influenced by prenatal environment
60
What is Food Neophobia & what would be the best way to help a child overcome it?
- Unwillingness to eat unfamiliar foods
- Introduce food 6-15 times
- DO NOT bribe or restrict the value of food bc then they'll overindulge when they get the chance
61
What is Associative Learning?
-Influencing unhealthy food choices by using characters to endorse them
62
Obesity is most common among what group?
- Blacks & latinos
| - Children in developing countries bc adopt the western diet of high fat &; sugar
63
How does Weight connect to Genetic Factors?
- Weight of adoptive kids are closely related to biological parents
- MZ are more similar that DZ
- Speed of eating shows heritability
64
How is Obesity Polygenetic?
- Genes affect the susceptibility of an increase in weight & how much food they eat
- Influences individuals temperament (regulates self & impulsive control) which is linked to executive function & cognitive control
65
What are the Environmental Influences that causes Obesity?
- Kids don't really get recess & eat food that's high in fat
- Less time exercising, more time in front of screens
- Less sleep=more prone to obesity
- Food deserts
66
What are the issues that Obese children face?
- Medical problems= heart disease, diabetes
| - Stereotypes & discrimination occurs as early as 1st grade
67
How does Malnutrition effect children?
- Contributes to nearly 50% of all deaths of children worldwide (most in asia &africa)
- Increases risk for infections
- Child who's severely underweight is 10x more likely to die of diarrhea
68
How does Malnutrition & Poverty effect children?
- Adversly effects all aspects of brain development
- Stunts more than 2 standard deviations below the mean
- Affects cognition, social development, productivity, educational attainment, quality of life
69
What are strategies that are working to improve Malnutrition?
- Improvment in maternal health
- Breast-feeding
- Supplements of key nutrients (Iodized salt, Iron, Vitamin A)
- Improved water sanitation
- Community based intervention
