Chapter 3

Front 1

Genotype:

Back 1

the genes that one inherits

Front 2

Phenotype:

Back 2

observable expression of the genotype

Front 3

environment

Back 3

an individual’s surroundings

Front 4

Parent’s genotype →child’s genotype

Back 4

Random assortment: During meiosis, before conception, each chromosome pair segregates independent of all other pairs.

Crossing over: sections of DNA switch from one chromosome to the other

•Promotes variability

•Some of the chromosomes that parents pass on to their offspring are constituted differently from their own.

Front 5

2. Child’s genotype →child’s phenotype

Back 5

How do genes promote development? •Call for the production of amino acids, the building blocks of proteins (e.g. melanin) •Guide cell differentiation •Regulate the pace and timing of development (regulator genes)

Front 6

Child’s genotype →child’s phenotype

traits

Back 6

Physical traits: characteristics of ones’ physical makeup •Behaviour traits: characteristics of the way one acts •Cognitive traits: one’s mental abilities and functions

Front 7

Child’s genotype →child’s phenotype

Types of genetic expressions

Back 7

Types of genetic expressions: •Single-gene inheritance patterns: human characteristics are determined by the action of a single gene •Polygenic inheritance patterns: human characteristics are determined by the action of many genes working together

Front 8

Gene expressions:

Back 8

About a third of human genes have two or more different forms, known as alleles

Front 9

Dominant allele:

Back 9

the form of the gene that is expressed if present

Front 10

Recessive allele:

Back 10

the form not expressed if a dominant allele is present

Front 11

homozygous

Back 11

A person who inherits two of the same alleles for a trait

Front 12

heterozygous

Back 12

A person who inherits two different alleles for a trait

Front 13

Codominance:

Back 13

condition in which two heterozygous but equally powerful alleles produce a phenotype in which both genes are equally and fully expressed.

E.g. Blood type: - Type A: dominant - Type B: dominant - Type AB

Front 14

sex-linked inheritance:

Back 14

determined by recessive genes located on the sex chromosomes

Males are more likely to inherit these recessive X-linked traits •E.g. Color-blindnes•hemophilia

Front 15

Polygenic inheritance:

Back 15

human characteristics/traits that are influenced by many pairs of alleles

E.g. Height, weight, intelligence, temperament, skin color, etc.

Front 16

Child’s environment →child’s phenotype

reaction range

Back 16

The range of phenotypic expression depending on different environments of different quality.

Front 17

The case of PKU (Phenylketonuria):

Back 17

a disorder that is related to a defective gene on chromosome 12 •Monogenic inheritance •Unable to metabolize phenylalanine •Lead to mental retardation •Need to be special low-phediet for life long

Front 18

Epigenetics

Back 18

Refer to changes in gene expression often mediated by environmentalinfluences•Traits that are heritable by daughter cells and not caused by changes in the DNA sequence

Front 19

skinny brown mouse study

Back 19

The effect of environment: diet•Fat yellow mice typically gave birth to fat yellow mice •The new diet triggered the methylation of the “fat” gene

Front 20

emotion stablity rat study (Emotional stability (calm vs. anxious ))

Back 20

s both epigenetic and genetic •The nurturing behavior of a mother rat during the first week of life shapes her pups' epigenomes•Highly nurtured rat pups àcalm adults •Neglected pubs à anxious adults

Front 21

4. Child’s phenotype →child’s environment

Back 21

active child theme:

•Children with different nature invoke different responses from the environment

•Children actively select environment to match their interests, talents and personality characteristics – their “environmental niches”

•Friendship: “birds of a feather flock together”

Front 22

The Family Study

Back 22

the mainstay of modern behavioral genetics research }A trait of interest is measured among groups of people who vary in genetic relatedness

Front 23

two types of twins

Back 23

Monozygotic (identical twin): develop from one zygote that splits and forms two embryos

•dizygotic (fraternal): develop from two separate eggs that are fertilized by two separate sperms

Front 24

Twin design study

Back 24

Are pairs of identical twins (monozygotic) reared together more similar to each other on various attributes than fraternal twins (dizygotic twins) reared together

Front 25

Adoption study

Back 25

esearchers examine whether adopted children are more like their biological or their adopted relatives

Front 26

Concordance rate

Back 26

The percentage of cases in which a particular attribute is present for one member of a twin pair if it is present for the other.

Front 27

Neurons

Back 27

Specialized cells that are the basic units of the brain’s information system

Front 28

Cell body:

Back 28

Contains the basic biological material that keeps the neuron functioning

Front 29

Dendrites:

Back 29

Receives input from other cells and conducts it toward the cell body

Front 30

Axon:

Back 30

Conducts electrical signals to connections with other neurons

Front 31

connections between neurons

Back 31

synapses

Front 32

Neurogenesis

Back 32

The proliferation of neurons through cell division, is largely complete by about 18 weeks after conception •Neurons migrate to their destinations, where they grow and differentiate•Axons elongate •Dendrites form spines that increase their capacity to form connections with other neurons •In the cortex, the most intense period of growth and differentiation occurs after birth

Front 33

Myelination

Back 33

Myelin sheath: formed by Glial cells, the brain’s white matter, around axons. •Insulate axons •Increase the speed and efficiency of information transmission •Begins before birth •Continue well into adulthood

Front 34

Synaptogenesis

Back 34

Each neuron forms synapses with thousands of other neurons, resulting in the formation of trillions of connection

Front 35

Synaptic Pruning

Back 35

The normal developmental process through which synapses that are rarely activated are eliminated

e.g. Heat stroke; Night terror •Second wave of synapse production and pruning in adolescents : may be linked to the impulsive, irrational behavior, which is characteristic of adolescence

Front 36

Brain Plasticity

Back 36

The capacity of the brain to be affected by experience •Experience plays a central role in determining which of the brain’s excess synapses will be pruned and which will be maintained •Synapses that are frequently activated are preserved, a process described as “neural Darwinism

Front 37

Experience-Expectant Plasticity

Back 37

wiring is a result of experience pro: fewer genes dedicated to development because experience will help recovering from injury, when one part is injured another part can take over con: when unused development is haulted

Front 38

Sensitive Periods

Back 38

A key element in experience-expectant plasticity is timing •There are a few periods when the human brain is particularly sensitive to particular kinds of external stimui

Front 39

sex chromosomes:

Back 39

chromosomes that decide gender

Front 40

mutation:

Back 40

a change in a section of DNA

Front 41

crossing over:

Back 41

the process by which sections of DNA switch from one chromosome to another

Front 42

regulator genes:

Back 42

genes that control the activity of other genes

Front 43

behaviour genetics:

Back 43

the science concerned with how variation in behaviour and development results from the combination of genetic and environmental factors

Front 44

Brain maturation

Back 44

there is a wave of pruning, grey matter increases dramatically and peaks around puberty then begins to decline as some of it is replaced by white matter

Front 45

dorsolateral profrontal cortext

Back 45

the last to mature

Front 46

experience dependent plasticity

Back 46

the more complex the environment the more neuron connections occur

Front 47

highly specific formation

Back 47

when environments require specific function more, e.g. brail = more corticol cells.

Front 48

brain damage and recovery

Back 48

children have higher chance of recovery because immature parts can mature to take over, this depends on the extent of the damge

Front 49

secular trends:

Back 49

changes in physical development have occured over generations

Front 50

failure to thrive

Back 50

a condition in which infants become malnourished and fail to grow

Front 51

infant feeding

Back 51

breastfeeding has many benefits but forumula feeding in the west is prevalant due to social reasons. there have been attempts to make breast feeding easier e.g. nursing stations.

Front 52

formula in developing and developed countries

Back 52

developing nations are poort because the water is bad, and it’s often diluted to stretch the product. formula in developed countries are good but they have more infections than breastfeed kids.

Front 53

where to food preferences come from

Back 53

innate preference can be evolutionary, come from mothers milk, observing other kids, and parents encouraging and rewarding.