Exam 1 Concepts Flashcards
(128 cards)
t or f: chronic diseases may consist of acute episodes
True
what disease is epstein barr virus linked to
mononucleosis
in chronic latent infection of EBV, how is it controlled?
it is controlled by the host immune system
what are post transplant lymphoproliferative disorders results of?
reactivation of latent ebv
what are the genetic programs realized by ebv?
Latency 1,2,3
t or f: ebv is found in all burkitt lymphomas and many ebv infected people have lymphomas
false: ebv is found in all burkitt lymphomas but many ebv infected people remain lymphoma free
what are ways to classify human disease according to genetics?
- chromosomal diseases
- single gene disorders
- polygenic (complex or multifactorial)
what are ways to find whether a certain disease has genetic components?
- use classical family study
- use twin studies
- use adoption studies
how does one conduct a classical family study?
- identify the family
- determine the proportion of the relatives affected
- calculate the lifetime risk
what is the relationship when describing the calculation of the lifetime expectation?
somewhat linear
what studies show greater risk to relatives of affected individuals than that of the population incidence?
family, twin, and adoption studies. This is due to genes being shared more with your relatives than a random stranger
what problem does using twin studies solve?
the problem of assigning the shares for genetic and environmental components
what is the rate of concordance in identical twins an important indicator of?
heritability
what is the concordance in genetic and environmental conditions for twins?
genetic conditios concordance is near 100% and environmental conditions it is never 0%
for multifactorial conditions, which has a greater concordance MZ or DZ?
MZ concordance is greater than DZ concordance in multifactorial conditions
what are the difficulties with twin studies?
- rarity of twins
- more concordant pairs of twins being enrolled in studies than discordant
- MZ twins often sharing environment more than DZ
how are difficulties of twin studies solved?
with the study of separated twins
how are adoption studies done?
- evaluating incidence of the disease in the biological relatives and adoptive relatives
- figure out relative importance of the genetic and environmental contributor
concerning human weight, genetic influences have an important role in determining what? what role does the family environment play?
genetics influences fatness in adults and family environment has no apparent effect
what human characteristics are inherited as normally continuously distributed?
weight, height , and skin color
T or F: heritability is the mode of inheritance
False: heritability is not the mode of inheritance, mode of inheritance is a fixed property of a trait but heritability is not
Pure environmental disease also could be viewed as what?
as determined by genes, such as having a pseudo lethal mutation causing trauma seeking behavior
what is the formula for total phenotypic variance?
Ve + Vg=Vp where Ve is the variance within identical genotypes, Vg is variance within identical environments and Vp is the total phenotypic variance
Liability to the condition is described as what?
as polygenic and normally distributed, if liability is above a threshold then they are affected