Exam 1

Question 1

concordance

Answer 1

the probability that the child has the condition given that the parent has the condition

Question 2

probands

Answer 2

the people serving as the starting point for examining family members

Question 3

selective placement

Answer 3

matching adoptive parents to adoptive children with respect to particular characteristics

Question 4

adoption study

Answer 4

information comes from separating genetic and environmental relationships

Question 5

twin study

Answer 5

manipulates the degree of genetic relationships while holding environmental relationship constant

Question 6

if genetics is the major source of difference between twins…

Answer 6

MZ twins will be more similar than DZ twins

Question 7

if environment is the major source of difference between twins…

Answer 7

MZ and DZ twins will be equally similar (when reared in same environment)

Question 8

liability-threshold model

Answer 8

risk is distributed normally, but disorder is only after a certain threshold is reached

Question 9

shared environment (C)

Answer 9

environmental factors siblings/twins share by virtue of their common rearing (makes family members MORE similar)

Question 10

nonshared environment (E)

Answer 10

environmental factors that siblings/twins do not share when reared together (makes family members dissimilar)

Question 11

equal environments assumption

Answer 11

assumes that treating MZ twins more similarly than DZ twins does not make them more similar to each other than DZ twins are for a certain trait

Question 12

biometrics

Answer 12

seeks to characterize the origins of individual differences by identifying the contributors to phenotypic variance

Question 13

heritability

Answer 13

the proportion of phenotypic variance that can be explained by genotypic variance within a particular population

Question 14

proportion of additive genetic variance (a^2)

Answer 14

a^2= 2(rMZ - rDZ)

Question 15

proportion of shared environmental variance (C^2)

Answer 15

c^2= 2(rDZ) - rMZ

Question 16

proportion of nonshared environmental variance (e^2)

Answer 16

e^2= 1 - rMZ

Question 17

MZ twins similarity (rMZ twin correlations)

Answer 17

rMZ= 1.0a^2 + 1.0c^2 + 0.0*e^2

Question 18

DZ twins similarity (rDZ twin correlations)

Answer 18

rDZ= 0.5a^2 + 1.0c^2 + 0.0*e^2

Question 19

heritability equations

Answer 19

h^2 OR a^2= A/A+C+E

Question 20

life course consistent

Answer 20

developmental type characterized by smaller groups and higher heritability

Question 21

adolescence limited

Answer 21

developmental type characterized by larger groups and lower heritability and more environmental influences

Question 22

Mendel’s 1st Law of Inheritance

Answer 22

each individual has two hereditary elements
offspring inherit one element from each parent
one element can be dominant over the other

Question 23

Mendel’s 2nd Law of Independent Assortment

Answer 23

inheritance of one gene is not affected by the inheritance of another gene

Question 24

recombinant types

Answer 24

new phenotypic combinations not seen in the parents

Question 25

linkage

Answer 25

when genes don’t independently assort

Question 26

recombination

Answer 26

occurs during cell division when chromosomes exchange parts

Question 27

Identity by Descent (IBD)

Answer 27

quantifies the extent to which siblings inherit the same alleles from the same parents

Question 28

polygenic trait

Answer 28

trait that is caused by more than one gene