Final Study Guide Flashcards
What is the single most cause of intellectual disability that is inherited?
defective fragile x gene
Prior to Charles Darwin’s Origin of Species theories, the prevailing hypothesis about lifeform adaptations was based on?
theology, argument from design, and creator’s wisdom
A locus that has several alternative possible nucleotide sequences is called?
single nucleotide polymorphism
Sickle cell disease is due to which point mutation?
missense
T/F: Mutations are always inherited
false
In eukaryotes, the first modification that happens to a transcript for stabilizing is?
5’ cap
During replication, discontinuous synthesis of DNA takes place on the __ __
lagging strand
Which childhood psychopathology is most influenced by genetic influence?
ADHD
What is a possible reason for individuals differences in behavior?
genetics and environment
Which of these is NOT inherited?
Huntington’s disease
Fragile X syndrome
Down syndrome
sickle cell anemia
Down syndrome
All transcripts begin with which codon?
AUG
Who is the scientist that is considered the father of modern behavioral genetics?
Francis Galton
Mendel’s first law of hereditary states?
each trait separates during reproduction - law of segregation
The importance of proper assessment in work on human heredity was first emphasized by who?
Francis Galton
Behavioral genetics combines what?
an individuals genetics and environmental influence
T/F: Huntington’s disease is an example of recessive inheritance
False
What led Francis Galton to conclude that mental characteristics are inherited?
Family study and quantitative measurements
Explain the PKU pedigree
No affected parents, only affected PKU person
The albino phenotype is an inherited trait that has behavioral consequences in mice. In the offspring of two carrier mice, the Mendelian phenotypic ratio of 3 normal to 1 albino is observed. How many genes does this suggest albinism is controlled by?
1
How is it possible that our roughly 25,000 genes can produce the hundreds of thousands of proteins made by the body?
alternate splicing of mRNA
What is the approximate size of the human genome?
3 billion basepairs
Down syndrome is caused by the presence of an extra copy of chromosome 21 and is also known as Trisomy 21. This is caused by?
Non-disjunction
T/F: CRISPR-Cas 9 is a genome editing technique
true
T/F: Gene expression is a complex and highly regulated phenomenon displayed by living organisms
true
A certain double DNA molecule is determined to have an adenine content of 26%. If this molecule undergoes replication, what % of cytosine will be in the newly synthesized DNA?
24%
How do you create an inbred strain of an animal model?
by mating brothers and sisters for several generations
Differences in rodent behavior induced by the mother are called?
maternal effects
Success of selective breeding program is reflected by?
separation between low and high lines is achieved
A nucleotide locus that has several alternative possible DNA sequences is called?
single nucleotide polymorphism
Changing the expression of specific genes without changing the underlying DNA sequence is called?
transcription
In a particular population of mice, certain individuals display a phenotype called ‘head-shaking’ (inherited as a dominant trait). Other mice display a recessive trait called ‘back-arching’ Which of these traits would be easier to eliminate from the mouse population by selective breeding?
head-shaking
What is quantitative trait locus?
a sequence of DNA that affects a trait
Siblings born at the same time and formed from the same zygote are?
identical (monozygotic) twins
Children reared in the same family but who are not genetically related are considered?
environmental relatives
What branch of genetics investigates causes of individual differences, without identifying specific genetic or environmental influences?
Behavioral genetics
What source of environmental variation that contributes to differences between family members?
nonshared environment
Which types of twins are expected to have the same genetic sequence?
Identical twins
Newly arisen, spontaneous change in offspring DNa sequence that are absent in the parents is called?
de novo mutation
What surrounds the embryo in the uterus and contributes to the prenatal environment?
Amnion
Goes amnion - chorion - placenta
What environment is a family environmental influence that produces similarity within the family?
shared environment
What is the ‘equal environments assumption’ in twin methodology?
environment is similar for identical and fraternal twins
Nature refers to?
genetics
Heritability can be reliably measured by?
SNP heritability method, effect size, and sample size
A 60% concordance between monozygotic twins means that if one of the twins has a condition, the chance that other twin will have the same condition is 60%
True
RNA interference technique is an example of what?
gene silencing
Mouse synteny homology is?
similarity between mouse and human gene localization
The genetic basis for schizophrenia was proved by?
adoption studies
T/F: CRISPR-Cas9 is a genome editing technique used for creating mouse models
true
Human behavior can be studied by?
twin method + adoption method
T/F: Heritability estimates are reliable when the effect size and sample size are large
true
Premutation is displayed in what condition?
Fragile X Syndrome
A tetranucleotide sequence GGTC in a certain DNA repeated 50 times is called?
microsatellite
A point mutation in the form of a nucleotide substitution within a gene sequence will result in the following change in the protein coded?
- amino acid remains the same
- an amino acid is substituted with a different amino acid
- truncated protein
Which disorder is resultant of an expansion of a trinucleotide which incorporates an extra amino acid in the protein sequence?
Huntington’s disease
T/F: Genetic anticipation is a phenomenon whereby a genetic disorder is passed on to the progeny with the symptoms becoming more severe
True
In a non-synonymous single nucleotide polymorphism occuring in a protein coding gene sequence…
the amino acid sequence changes
An expanded number of triplet repeats of DNA that does not itself result in a disorder, but which predisposes offspring for the disorder is called?
premutation
Epigenetics refers to?
methylation of cytosine residues
T/F: Epigenetic marks are inherited from both parents
False; not inherited at all
Gene expression is regulated by?
transcription control, RNA stability, and RNa interference
T/F: The phenomenon of genomic imprinting is caused by core histone modifications
False; silenced by epigenetic tags
The tendency of DNA sequences that are close on a chromosome to be inherited together during the meiosis phase of sexual reproduction is called?
linkage
In females, one of the X chromosomes undergoes change into a heterochromatin by?
expression of a non-protein coding RNA, long non-coding RNA
RNA interference can result in?
instability of the mRNA, translational repression, heterochromatin formation
What is transcriptomics?
A technique that globally analyses all the mRNA in a tissue
Proteins in a complex mixture can be effectively resolved by using?
two-dimensional gel electrophoresis
T/F: A junction between two glial cells through which impulses pass by diffusion of a neurotransmitter is a synapse
false
Siblings born at the same time and formed from separate zygotes are?
fraternal (dizygotic) twins
T/F: Cognitive disabilities are often reflected in single gene disorders
True
Huntington disease is caused by which type of mutation?
CAG repeat in the exons
T/F: The performance of maze dull mice can be improved by placing them in a restrictive environment
False
The phenomenon of genomic imprinting refers to?
silencing of one of the allele for a gene’s expression
T/F: Rodent models are inbred for several generation to separate individual phenotypes
true
T/F: Tyrosine in the diet can be regulated to control the severity of PKU
False; phenylalanine
T/F: PKU is NOT an inherited disorder
False
What are the three stop codons?
UAG
UGA
UAA
What are Mendel’s three laws?
Law of Dominance + Uniformity
Law of Independent Assortment
Law of Segregation
What is the law of dominance?
Some genes are dominant over others
What is the law of independent assortment?
alleles of different genes segregate independently of one another during gametogenesis and are distributed independently of one another in the next generation
Nurture refers to?
environment
What is genomic imprinting?
process by which only one copy of a gene in an individual (either from their mother or their father) is expressed, while the other copy is suppressed.
Fragile X syndrome is caused by?
a CGG repeat in the 5’ untranslated region of the FMR1 gene
Describe the pedigree for Huntington’s
one affected parent yields to affected children
Describe the parental affect of people with PKU v Huntingtons
PKU: no parent affected, recessive
HD: always one parent affected, dominant
What is the risk of getting Huntington’s
50%
What is the risk of getting PKU?
25%
What are the criteria for Hardy-Weinberg equilibrium?
no natural selection
random mating
large population
no gene flow from other populations
X-linked recessive traits tend to participate in this phenomenon?
skip a generation
What is the difference between exons and introns?
exons: protein coding regions
introns: intergenic sequences
Explain the central dogma of DNA
DNA -> RNA synthesis (transcription)
RNA -> protein synthesis (translation)
protein
What are the three steps of mRNA processing?
5’ capping
intronic sequence splicing
3’ polyadenylation
What is broad-sense heritability
all sources of genetic variability, whether genes operate in an additive manner or not
What is narrow-sense heritability
phenotypic variability explained by additive genetic effects
Define endophenotype
term used to separate behavioral symptoms into more stable phenotypes with a clear genetic connection
