1.)Give two reasons why the heritability estimate for a trait might differ betwe
ID: 38292 • Letter: 1
Question
1.)Give two reasons why the heritability estimate for a trait might differ between two studies.
2.)443 individuals with bipolar disorder have 845 siblings. Of these 845 siblings, 225 also have bipolar disorder. If the prevalence of bipolar disorder in the United States is 4.4%, what familial relative risk ratio (?)?
2a.) According to your calculations, does bipolar disorder run in families? Is this relative risk ratio a result of shared genetics or environment?
3.)In a study of Chilean twins, the correlation between risk taking personality was found to be 0.74 in monozygotic twins, and 0.43 in dizygotic twins. What is the heritability? Is this broad-sense or narrow-sense heritability?
4.)What are two assumptions of twin studies and how might they be violated?
5.) Studies on the heritability of intelligence and personality traits generally find that:
A.) identical twins raised apart are about as similar as fraternal twins raised together
B.) identical twins raised apart are about as similar as those raised together
C.) identical twins raised apart are very different from those raised together
D.)fraternal twins raised apart are very different from those raised together
Explanation / Answer
Answer:
1)A:
Heritability is the proportion of observed differences on a trait among individuals of a population that are due to genetic differences. Factors including genetics, environment and random chance can all contribute to the variation between individuals in their observable characteristics (in their "phenotypes").[1] Heritability thus analyzes the relative contributions of differences in genetic and non-genetic factors to the total phenotypic variance in a population. For instance, some humans in a population are taller than others; heritability attempts to identify how much genetics play a role in part of the population being taller.
Heritability is measured by estimating the relative contributions of genetic and non-genetic differences to the total phenotypic variation in a population. Heritability is an important concept in quantitative genetics, particularly in selective breeding and behavior genetics (for instance, twin studies), but is less widely used in population genetics.
2)A:
Diagnostic and Statistical Manual of Mental Disorders, clinicaljudgement that will take into account the level of impairment, pervasiveness andindividual factors, as well as family, social and cultural contexts.
Bipolar I disorder occurs approximately equally in both sexes. The symptom profile may differ between men and women,there is some evidence that women tend to experience more episodes of mixed or dysphoric mania than men.
but the above experiment shows the results women:men are in the ratio might be like 60:40.
2a)A:
Though the exact cause of bipolar disorder has yet to be found, scientists confirm that bipolar disorder has a genetic component, meaning the disorder can run in families. Some research suggests that multiple factors may interact to produce abnormal function of brain circuits that results in bipolar disorder's symptoms of major depression and mania. Examples of environmental factors may include stress, alcohol or substance abuse, and lack of sleep.
3)A:
Febrile seizures (FSs) occur in children older than 1 month and without prior afebrile seizures in the absence of a central nervous system infection or acute electrolyte imbalance. Their pathogenesis is multifactorial. The most relevant familial studies evidence an occurrence rate ranging from 10% to 46% and median recurrence rate of 36% in children with positive familial history for FS. The main twin studies demonstrated a higher concordance rate in monozygotic twins with FS than in dizygotic ones. Linkage studies have proposed 11 chromosomal locations responsible to FS attributed to FEB1 to FEB11. Population-based association studies have shown at least one positive association for 14 of 41 investigated genes with FS. The proinflammatory cytokine interleukin 1? (IL-1?) was the most investigated and also gene associated with susceptibility to FS. A possible role in the overlapping of epilepsy and FS was found for 16 of 36 investigated genes. SCN1A, IL-1?, CHRNA4, and GABRG2 were the most commonly involved genes in this context. The genetic background of FS involves the regulation of different processes, including individual and familial susceptibility, modulation of immune response, and neuronal excitability and interactions with exogenous agents such as viruses.
4)A:
Twin studies reveal the absolute and relative importance of environmental and genetic influences on individuals in a sample. Twin research is considered a key tool in behavioral genetics and in content fields, from biology to psycholog Twin studies are part of the methods used in behavior genetics, which includes all data that are genetically informative
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.