GN 301 Final Exam Questions with Verified Solutions Graded A+
Characteristics of Quantitative Traits - Answers Many genes control the trait (polygenic),
multifactorial (affected by environment), continuously variable (height/weight)
examples of multifactorial traits - Answers eye color, weight, height, hair color
threshold traits - Answers once a specific point/threshold is crossed, the traits phenotype is
expressed
quantitative trait - Answers a measurable phenotype that depends on the cumulative actions of
many genes and the environment, resulting in a continuous range of variation
monozygotic vs dizygotic twins - Answers *monozygotic* two develop from one zygote
(identical, same genetics)
*dizygotic* two develop from two zygotes (fraternal, different genetics)
how do you determine differences between mono and dizygotic - Answers genetic testing,
physical similarities, looking at placentas on early ultrasound, blood types
super twins - Answers second pregnancy occurs while a women is already pregnant, born at the
same time but fertilized at different times
heritability - Answers the proportion of phenotypic variation that is due to genetic effects (the
rest due to environment)
characteristics of heritability - Answers ranges from 0-1, 0 being all variation in phenotypes due
to environmental effects and 1 being all variation due to genetic effects
MZ reared together - Answers share nearly identical genes and largely similar environment
MZ reared apart - Answers share nearly identical genes but have different environments
DZ reared together - Answers share ~50% of genes and share environment
DZ reared apart - Answers share ~50% of genes but grow up in different environments
concordance studies - Answers use twins to measure the probability that two individuals in a
pair will share a trait, determining heritability of diseases and other characteristics and effect of
environment (MZ vs DZ)
Genome-wide Association Studies - Answers identify QTLs by surveying a large group of ppl to
find genetic variations such as SNPs, that are associated with specific phenotypes
QTLs - Answers quantitative trait loci, which are chromosomal regions linked to complex traits
like disease susceptibility or yield
, SNPs - Answers single nucleotide polymorphism, can be used during gene chip/microarray to
identify candidate genes
candidate genes - Answers a gene suspected of playing a role in a specific trait or disease
based on its function or genomic location
IQ - Answers 2/3 of population 85-115 (avg=100)
Intellectually disabled if IQ is less than 70 (~3% of pop.)
gifted>125
multifactorial aspects of a low IQ - Answers prenatal and early childhood health, socioeconomic
status, parental education, brain structure, poor nutrition, exposure to toxins, healthcare and
education
Abnormalities in chromosome number and structure that can cause low IQ - Answers Down
syndrome (21), deletion/duplication such as Wolf-Hirschhorn and Williams syndrome
down syndrome - Answers extra chromosome 21 (trisomy 21), physical and intellectual
disabilities, occurs randomly, maternal age is a risk factor, low muscle tone, upward slanting
eyes, flattened face
wolf-hirschhorn syndrome - Answers deletion on chromosome 4, distinctive facial features,
delayed growth and development, seizures, large wide-spaced eyes, broad nasal bridge, small
chin and head
williams syndrome - Answers deletion of 26-28 genes on chromosome 7, developmental issues,
heart problems, very sociable, strong verbal skills, full cheeks, wide mouth, puffy eyes
Mental health - Answers 1 in 10 will be hospitalized for mental health disorder
50% of hospital beds are filled with mentally ill
what do neuroglia cells do - Answers support and protect neurons by providing nutrients,
creating myelin sheath, maintaining homeostasis, and performing immune functions, 1 trillion of
them
neuron communication across synapses with neurotransmitters such as - Answers dopamine,
serotonin, norepinephrine
4 areas of gene action - Answers additive, dominance, epistatic, and overdominance
parkinsons - Answers clear mind but loss of control over body muscles, cannot properly
metabolize dopamine, D or R, environmental effects, family history doesn't matter
epilepsy - Answers caused by variations in genes that affect the brain's electrical signaling,
Characteristics of Quantitative Traits - Answers Many genes control the trait (polygenic),
multifactorial (affected by environment), continuously variable (height/weight)
examples of multifactorial traits - Answers eye color, weight, height, hair color
threshold traits - Answers once a specific point/threshold is crossed, the traits phenotype is
expressed
quantitative trait - Answers a measurable phenotype that depends on the cumulative actions of
many genes and the environment, resulting in a continuous range of variation
monozygotic vs dizygotic twins - Answers *monozygotic* two develop from one zygote
(identical, same genetics)
*dizygotic* two develop from two zygotes (fraternal, different genetics)
how do you determine differences between mono and dizygotic - Answers genetic testing,
physical similarities, looking at placentas on early ultrasound, blood types
super twins - Answers second pregnancy occurs while a women is already pregnant, born at the
same time but fertilized at different times
heritability - Answers the proportion of phenotypic variation that is due to genetic effects (the
rest due to environment)
characteristics of heritability - Answers ranges from 0-1, 0 being all variation in phenotypes due
to environmental effects and 1 being all variation due to genetic effects
MZ reared together - Answers share nearly identical genes and largely similar environment
MZ reared apart - Answers share nearly identical genes but have different environments
DZ reared together - Answers share ~50% of genes and share environment
DZ reared apart - Answers share ~50% of genes but grow up in different environments
concordance studies - Answers use twins to measure the probability that two individuals in a
pair will share a trait, determining heritability of diseases and other characteristics and effect of
environment (MZ vs DZ)
Genome-wide Association Studies - Answers identify QTLs by surveying a large group of ppl to
find genetic variations such as SNPs, that are associated with specific phenotypes
QTLs - Answers quantitative trait loci, which are chromosomal regions linked to complex traits
like disease susceptibility or yield
, SNPs - Answers single nucleotide polymorphism, can be used during gene chip/microarray to
identify candidate genes
candidate genes - Answers a gene suspected of playing a role in a specific trait or disease
based on its function or genomic location
IQ - Answers 2/3 of population 85-115 (avg=100)
Intellectually disabled if IQ is less than 70 (~3% of pop.)
gifted>125
multifactorial aspects of a low IQ - Answers prenatal and early childhood health, socioeconomic
status, parental education, brain structure, poor nutrition, exposure to toxins, healthcare and
education
Abnormalities in chromosome number and structure that can cause low IQ - Answers Down
syndrome (21), deletion/duplication such as Wolf-Hirschhorn and Williams syndrome
down syndrome - Answers extra chromosome 21 (trisomy 21), physical and intellectual
disabilities, occurs randomly, maternal age is a risk factor, low muscle tone, upward slanting
eyes, flattened face
wolf-hirschhorn syndrome - Answers deletion on chromosome 4, distinctive facial features,
delayed growth and development, seizures, large wide-spaced eyes, broad nasal bridge, small
chin and head
williams syndrome - Answers deletion of 26-28 genes on chromosome 7, developmental issues,
heart problems, very sociable, strong verbal skills, full cheeks, wide mouth, puffy eyes
Mental health - Answers 1 in 10 will be hospitalized for mental health disorder
50% of hospital beds are filled with mentally ill
what do neuroglia cells do - Answers support and protect neurons by providing nutrients,
creating myelin sheath, maintaining homeostasis, and performing immune functions, 1 trillion of
them
neuron communication across synapses with neurotransmitters such as - Answers dopamine,
serotonin, norepinephrine
4 areas of gene action - Answers additive, dominance, epistatic, and overdominance
parkinsons - Answers clear mind but loss of control over body muscles, cannot properly
metabolize dopamine, D or R, environmental effects, family history doesn't matter
epilepsy - Answers caused by variations in genes that affect the brain's electrical signaling,
