Introduction to Human Behavioral
Genetics
University of Minnesota
Coursera
Notes + Quiz questions
Module 2 - 5
,Table of contents
Module 2 .................................................................................................................................... 3
Module 3 .................................................................................................................................. 11
Module 4 .................................................................................................................................. 18
Module 5 .................................................................................................................................. 23
, Module 2
Question 1
Which of the following statements is true?
A) Fertility treatments equally increase the likelihood of MZ and DZ twin births.
B) Monochorionic twins are not systematically more similar than dichorionic twins.
C) Rates of DZ twinning are higher in women of Asian ancestry than in woman of African
or European ancestry.
D) The father’s ethnic background affects the rate of twinning in MZ twins but not in DZ
twins.
DZ twins are always dichorionic. 1/3 of MZ twins are
dichorionic.
Monochorionic MZ twins can lead to differences. One
twin transfuses the other, the donor twin is denied
nutrients by donating to the other twin → (twin to twin
transfusion syndrome)
Dichorionic means two placentas. Mono means one.
Question 2
Concordance can range from _______. Correlation can range from ________.
A) -1 to 1; -1 to 1 (negative one to one; negative one to one)
B) 0 to 1; -1 to 1 (zero to one; negative one to one)
C) 0 to 1; 0 to 1 (zero to one; zero to one)
D) -1 to 1; 0 to 1 (negative one to one; zero to one)
Concordance: the probability a twin has the condition
given her/his cotwin has the condition
Interpretation: Estimates risk of condition in cotwin
Range: Theoretically, can vary from 0% to 100%. In practice, rarely lower than population
prevalence.
Correlation: An index of strength of linear relationship between two quantitative scores.
Range: Theoretically, can vary from -1.0 (perfect negative) to +1.0 (perfect positive). In
practice, twin correlation usually varies from 0.0 (no relationship) to +1.0.
Genetics
University of Minnesota
Coursera
Notes + Quiz questions
Module 2 - 5
,Table of contents
Module 2 .................................................................................................................................... 3
Module 3 .................................................................................................................................. 11
Module 4 .................................................................................................................................. 18
Module 5 .................................................................................................................................. 23
, Module 2
Question 1
Which of the following statements is true?
A) Fertility treatments equally increase the likelihood of MZ and DZ twin births.
B) Monochorionic twins are not systematically more similar than dichorionic twins.
C) Rates of DZ twinning are higher in women of Asian ancestry than in woman of African
or European ancestry.
D) The father’s ethnic background affects the rate of twinning in MZ twins but not in DZ
twins.
DZ twins are always dichorionic. 1/3 of MZ twins are
dichorionic.
Monochorionic MZ twins can lead to differences. One
twin transfuses the other, the donor twin is denied
nutrients by donating to the other twin → (twin to twin
transfusion syndrome)
Dichorionic means two placentas. Mono means one.
Question 2
Concordance can range from _______. Correlation can range from ________.
A) -1 to 1; -1 to 1 (negative one to one; negative one to one)
B) 0 to 1; -1 to 1 (zero to one; negative one to one)
C) 0 to 1; 0 to 1 (zero to one; zero to one)
D) -1 to 1; 0 to 1 (negative one to one; zero to one)
Concordance: the probability a twin has the condition
given her/his cotwin has the condition
Interpretation: Estimates risk of condition in cotwin
Range: Theoretically, can vary from 0% to 100%. In practice, rarely lower than population
prevalence.
Correlation: An index of strength of linear relationship between two quantitative scores.
Range: Theoretically, can vary from -1.0 (perfect negative) to +1.0 (perfect positive). In
practice, twin correlation usually varies from 0.0 (no relationship) to +1.0.
