Most traits are Trigenic, monogenic, or polygenic?
Homozygous vs heterozygous
Polygenic
Homozygous - 2 dominant genes
Heterozygous - 1 dominant and 1 recessive gene
Farsightedness requires x amount of what kind of gene
Nearsightedness requires x amount of what kind of gene
one dominant
Two recessive
Heritability estimate
Variation of phenotype w/in a group resulting from differences in genotype
Heredity accounts for ____ % of variability for many characteristics
50%
List and briefly explain Brofenbrenner’s Ecological Model
1) Microsystem - immediate environment
2) Mesosystem - how diff elements w/in immediate environment interact
3) Exosystem - Elements in broader environment (teachers, parents’ jobs)
4) Macrosystem - Overarching environmental influences (culture, religion)
5) Chronosystem - Events over lifespan
Rutter’s risk indicators
1 or none of these increase risk by ___% whereas 4 or more of these increases risk by ____ %
Marital discord, parental criminality, socioeconomic status, large family, maternal psych dx, placement outside of home
2% and 21%
Werner et al longitudinal study of infants with/without prenatal and perinatal stress. What did it imply about high-risk children?
More physical/cognitive issues for infants with stress but differences declined over time. This implies resilience in high-risk children
Explain reaction range in the context of ability to compensate for birth defects
Those with a defect of mild cognitive impairment have a broader reaction range than those with severe, so mild impairment leaves room for a better response to a good environment
What is Genotype-Environment Correlation and what are the 3 main types?
How are they relatively important over the lifespan?
genetics affects the environment one is exposed to which reinforces genetics
1) Passive – parents give environment that encourage development of traits
2) Evocative – child’s traits evoke reactions that reinforce child’s genetics
3) Active – aka niche picking – child actively seeks out genetically reinforcing experiences
Relative importance changes over time
Explain ethology and how it differs from evolutionary theory
Ethology is animal behavior in natural habitats and while it focuses on adaptive instincts, evolutionary theory focus on mental/emotional adaptations
Evolutionary theory says that many psychological mechanisms are _______, which means they help us to deal with specific types of problems encountered in the environment and others were _____, designed to help us at certain points in our lives.
Domain-specific, adaptive
What/when are the 3 stages of prenatal development? And, which stage is most vulnerable to damage by teratogens?
1) Germinal - the fertilized ovum is called a zygote
2) Embryonic - 3rd week to 8th week (teratogens worst here)
3) Fetal - 9th week until birth
Birth defects can be caused by three factors:
1) Chromosomal disorders
2) Exposure to teratogens
3) Poor maternal health
Chromosomal Disorders
All human cells contain ___ chromosomes arranged in ___ pairs. Of these pairs, _____ are referred to as ______and the ____ one is the ___ chromosome.
46 chromosomes, 23 pairs
22, autosomes, 23rd, sex
When a disorder is carried on an autosome it is referred to as an _______, and when it’s on the 23rd one it’s referred to as a ______
autosomal disorder, sex-linked
Disorders due to dominant/recessive genes
Dominant gene disorders are due to the inheritance of a _________ from one or both parents?
Recessive gene disorders are due to the inheritance of a pair of _________ from one parent or one from each parent?
single dominant gene from one parent
recessive genes (one from each parent)
Examples of dominant and recessive gene disorders:
Dominant - Huntington’s
Recessive - Phenylketonuria (PKU), cystic fibrosis, sickle cell, Tay-Sachs disease
Disorders due to a Chromosomal Abnormality can be due to 2 factors:
1) Variation in # of chromosomes (aneuploidy)
2) Alteration in the structure of chromosomes
Disorders due to variation in # of chromosomes:
Down syndrome, Klinefelter syndrome, Turner syndrome
Down syndrome represents an extra ___ chromosome
Klinefelter and Turner syndromes are caused by an abnormality in the # of ____ chromosomes. Briefly explain them.
21st
Sex
Klinefelter - only males - 2 or more X chromosomes and 1 Y chromosome - small penis and testes, dvlpmt of breasts, sterile
Turner - only females - single x chromosome - short in stature, webbed neck, drooping eyelids
Alterations in chromosome structure include:
Deletions, translocations, and inversions
Deletion - a part of a chromosome is missing
Translocation - transfer of a chromosome segment to another chromosome
Inversion - Chromosome breaks in 2 places and the segment formed inverts (turns upside down) and reattaches to the chromosome
When is exposure to teratogens the most dangerous?
During the embryonic stage (weeks 3-8)
Some teratogens and their effects:
Alcohol: could lead to Fetal Alcohol Spectrum Disorder, which in order of severity (greatest to least) includes:
a. Fetal Alcohol Syndrome (FAS)
b. Alcohol-related neurodevelopmental Disorder (ARND)
c. Alcohol-related birth Defects (ARBD)
Cocaine: spontaneous abortion/stillbirth, seizures, reduced head circumference, exagerated startle response
Nicotine: placental abnormalities, respiratory isues, SIDS, social/cognitive issues
Lead: Intellectual disability
*All low birth weight
Maternal conditions and birth defects include:
1) Rubella - blindness, deafness, heart/intellectual issues
2) Cytomegalovirus - intellectual issues, hearing/visual issues
3) HIV/AIDS - 20-30% change of transmitting HIV - with drug therapy, 50% of kids survive beyond age 10
4) Malnutrition - low weight, stillbirth, poor immune
5) Stress - miscarraige, painful labor, irregular feeding, sleeping, and bowel habits, low birth weight