Quiz 2 Flashcards
Physiological-or-psychological thinking was given official recognition in the 17th century when the Roman Church officially supported:
Cartesian dualism.
_____ many European ethologists, most of the early North American experimental psychologists were committed to the _________ side of the nature–nurture debate.
Unlike; nurture
European ethology focused on the study of
instinctive behaviors.
Asomatognosia typically involves the _____ side of the body and usually results from damage to the _____________.
left; right parietal lobe
In Gallup’s (1983) research with chimpanzees, the chimpanzees were given access to a mirror. Later the chimpanzee’s eyebrow was painted red. When the chimpanzees now looked at the mirror, they _________, suggesting that _____.
demonstrated awareness of the red color by touching their eyebrows; chimpanzees have self-awareness
The two genes that control each trait are called:
alleles.
In his groundbreaking experiments, Mendel studied __________ traits in true-breeding lines of pea plants.
dichotomous
Each strand of DNA is a sequence of ________ bases.
nucleotide
The massive international research effort that mapped the sequence of bases in human chromosomes was the Human _____________ Project.
Genome
Mechanisms that influence the expression of genes without changing the genes themselves are often called:
epigenetic mechanisms.
_____________ is the development of individuals over their life span, whereas _______________ is the evolutionary development of species through the ages.
Ontogeny; phylogeny
When Searle (1949) compared selectively bred maze-dull and maze-bright rats on 30 different behavioral tests, his analysis suggested that the maze-bright rats were superior maze learners not because they were more intelligent but because they:
were less fearful.
The PKU gene is ________, meaning that _______________.
recessive; it develops only in homozygous individuals
Which statement is true of the neurological disorder phenylketonuria (PKU)?
It is more common among children of European American descent than among children of African American or Asian American descent.
The period, usually early in life, during which a particular experience must occur to have a major effect on the development of a trait is called the _____ period for that trait.
sensitive
_________ twins develop from the same zygote, whereas ________ twins develop from two zygotes.
Monozygotic; dizygotic
Heritability estimates tell us about:
the proportion of variability that occurred in a particular trait in a particular study as a result of the genetic variation in that study.
he discovery that genetic variability contributes substantially to individual differences in virtually all human traits and behaviors has led several geneticists to argue that:
no more heritability estimate studies should be conducted.
Fraga and colleagues (2005) took tissue samples from 40 pairs of monozygotic twins and screened the tissues for DNA methylation and histone modifications. They found that the twins were epigenetically _________________ early in life and that epigenetic differences _______________________ as they aged.
indistinguishable; accumulated
The discovery of epigenetic differences in monozygotic twins raises the possibility that epigenetic differences may explain why:
one twin develops a trait and the other doesn’t.
The study of animal behavior in the wild is called:
ethology.
In an attempt to provide convincing evidence of self-awareness, Gallup (1983) devised a clever test: Each chimpanzee in his experiment was:
put in front of a mirror.
Darwin was the first to:
amass a large body of supporting evidence for evolution.
One reason why social dominance is an important factor in evolution is that:
in some species, dominant females are more likely to produce more and healthier offspring.
Apes are thought to have evolved from a line of:
Old-World monkeys.
The evolution of the scrotum illustrates that evolution:
does not progress to preordained perfection.
During the course of evolution of the human brain, there has been a(n) ______ in the ______.
increase; number of convolutions
Marco possesses two different variants, or _____, of the eye-color gene: a brown-eyed and a blue-eyed variant. Marco is _______ for the trait of eye color.
alleles; heterozygous
Humans have __________ pairs of chromosomes.
23
Proteins are long chains of:
amino acids
__________________ is the study of all mechanisms of inheritance other than the genetic code and its expression.
Epigenetics
In a classic study by Cooper and Zubek (1958), maze-dull rats made significantly more errors than maze-bright rats only if they had been reared in:
an impoverished environment.
In most modern hospitals, the blood of newborn infants is routinely screened for:
high levels of phenylalanine.
In the representative Western samples that have been studied, all complex traits and behaviors have heritability estimates ranging from ______ percent.
40 to 80
In studies of disease-discordant monozygotic twin pairs, one searches each pair for __________________, focusing on those areas of DNA that are thought to be involved in the disorder.
epigenetic differences
How do genes yield traits (how does genotype become phenotype)? That is, what are the biological processes that lead to synthesis of cell proteins such as receptors and ion channels?
DNA → (Transcription) → RNA →(Translation) → Protein → Trait
What gene in the amygdala contributes to neuroticism?
The gene that encodes GABA receptors
If the gene that encodes GABA receptors is highly expressed in Person A, but not Person B, who is more neurotic?
Person B
If Person B’s amygdala neurons make some GABA receptors, but Person A’s makes more which results in lower neural firing for Person A , who is more neurotic?
Person B
What type of individual would result from neurons making some GABA receptors
-Risk adverse
What type of individual would result from neurons making more GABA receptors which results in lower neural firing
-Bold & fearless
What are environmental influences that could contribute to someone having high or low levels of neuroticism?
Traumatic experiences, such as having a bad fall off of the climbing wall, could lower someone’s GABA receptor amount
A genetic mechanism by which two people could differ in their adult levels of anxiety/fear (neuroticism) is:
- They could have inherited genes from their biological parents that predispose them to greater/lesser anxiety/fear
- They could have had different experiences in life that caused different epigenetic changes in their amygdala gene expression
One specific molecular mechanism that could underlie high anxiety in H.B. vs. low anxiety in R.T. is:
H.B.’s gene that encodes for the GABA receptor protein in her amygdala is turned off most of the time, so her amygdala neurons fire a lot, whereas R.T.’s gene that encodes for the GABA receptor protein in her amygdala is turned on most of the time, so that her amygdala neurons fire at a low rate most of the time
Two mechanisms at the DNA level that can result in increased or decreased gene expression (i.e., that can turn genes on or off) after birth
- DNA Methylation
- Histone remodeling
DNA demethylation
- If this occurs, transcription and translation go up
- Increased gene expression
Histone remodeling
- The core around which RNA wraps changes shape –> influences the shape of adjacent DNA
- Increase or decrease in gene expression
What happened to the performance of “maze-dull” vs. “maze-bright” when they are raised by parents who perform differently on tasks?
It didn’t work
What happened when a “maze-dull” rat was placed in an enriched environment?
The rat performed about as well as the “maze-bright” rat
What happened when an already “maze-bright” rat was placed in an enriched environment?
No impact
Selective breeding of “maze-bright” and “maze-dull” rats demonstrates what about nature (genes at birth) vs. nurture (genes in adulthood)?
Genetic background that predisposes to “maze-dullness” can be largely overcome by enriching experiences after birth
What is the genetic basis of PKU (phenylketonuria)?
- Genetic disorder inherited from an individual’s parents
- Due to mutations in the PAH gene, which results in low levels of the enzyme phenylalanine hydroxylase. This results in the buildup of dietary phenylalanine to potentially toxic levels
What can PKU (phenylketonuria) impact?
Intellectual problems/abnormal brain development
How can environmental (dietary) adjustment compensate for this gene abnormality?
Providing the kids with phenyl-free foods can prevent kids from suffering from the full blown disorder
How does PKU (phenylketonuria) work?
If the gene that codes for enzyme that converts phe to tyr is non-functional → body cannot synthesize DA (from tyr) → abnormal brain development
For a long time, heritability estimates for various traits such as intelligence were misleading, because they were determined from:
A relatively select (non-diverse) sample of identical twins raised apart vs. together
How can studies of monozygotic (identical) twins be used to help us better understand how environment influences traits/disease as we age?
Epigenetic differences as they age
How to test epigenetic studies of monozygotic (identical) twins
Periodic DNA sampling to screen for methylations and histone modifications
Should monozygotic twins be referred to as identical twins?
To be precise, not exactly - as they grow, each twin’s experiences change their epigenetic profiles
