Psych test 2 Flashcards
What are chromosomes made of?
DNA
What do cells contain?
chromosomes
How many chromosomes do we have?
46 chromosomes, 23 pairs
one from mom, one from dad
genotype
a persons genetic inheritance
phenotype
a persons characteristics which comes from the genotype
dominant-recessive inheritance
dominant influences genotype
recessive only influences if paired with another recessive
form of a gene
an allele
when does dominant recessive inheritance happen?
only for traits determined by a single gene
incomplete dominance
phenotype primarily influenced by the dominant gene
Example: sickle cell anemia
Ss - sickle cell
resistant to malaria
polygenic inheritance
when two or more genes affect the expression of one trait
What sex chromosomes do women have?
XX
What chromosomes do men have?
XY
Why are men more vulnerable to recessive disorders linked to the x chromosomes?
They have an xy chromosome so they don’t have another x to bump off the x linked disorders
behavior genetics
goal is to identify how much genes influence behavior
MZ twins
identical; share 100% of genes
DZ twins
fraternal; share 50% of genes
heritability
an estimate of the extent to which genes are responsible for differences among people within a specific population
What percentage of population differences can we get from environmental and genetic
.70 = genetic factor is estimated to contribute 70%
environmental = 30%
intelligence heritability factor = .50
what family is the heritability of intelligence higher?
middle-income families > lower income
concordance rate
degree of similarity in phenotype among pairs of family members
What is the percent of twin B developing schizophrenia if twin A has it? MZ twins
50%
What is the percent of twin B developing schizophrenia if twin A has it? DZ twins
18%
epigenetics
development results from bidirectional interactions between genotype and environment
gilbert gottlieb
there is not a single, predetermined path for any developmental outcome
reaction range
range of possible developmental paths established by genes; environment determines where development takes place within that range
Drs Sandra Scarr & Kathleen McCartney Theory
genes influence the kind of environment we experience
passive genotype
occur when parents provide the genes and environment
evocative effect
occur when inherited characteristics evoke responses from others
active genotype
when people seek out environments that corresponds to their genotypic characteristics = niche-picking
passive - childhood
more pronounced
active - childhood
relatively weak
passive - adolesence
less pronounced
active - adolescence
increase
passive - adulthood
fades entirely
active - adulthood
most pronounced
evocative
stable throughout life
embryonic disk (inner layer)
will become an embryo
outer layer
trophoblast provides nourishment and protects embryo
embryonic disk layers
ectoderm
endoderm
mesoderm
ectoderm
skin, hair, nails, sensory and nervous systems
mesoderm
muscular, reproductive, and circulatory
conception
union of gametes
Germinal period
first two weeks after conception
What happens the first week of the germinal period?
rapid cell division
embryonic disk (inner layer) = will become embryo
outer layer = nourishes and protects
What develops during the germinal period?
umbilical cord, placenta, amnion
embryonic period
weeks 3-8 (weeks 5-8 of pregnancy)
What develops during the embryonic period?
embryonic disk
nervous system
circulatory system
digestive system
lungs
skin
muscle
What is developed at the end of the embryonic period?
main body parts
main organs
sexual differentiation
Fetal period
week 9 (week 11 of pregnancy) to birth
what is developed at the end of the fetal period?
genitals formed
fingernails, toenails, tastebuds
heartbeat heard through stethoscope
1st trimester
weeks 9-12
2nd trimester
weeks 13-24
Movement felt by mother (kicks, turns)
Breathes amniotic fluid, sucks thumb Responds to sounds
3rd trimester
weeks 24-38
Lungs fully develop
Weight gain!
Brain development continues sleep-wake
cycles like newborn
Awareness of external environment
viability
ability to survive outside the womb
whats the last major organ to develop?
the lungs
