Research studies focusing on genetic factors in schizophrenia have found that
a. an individual with a schizophrenic identical twin has the highest risk factor (almost 50 percent) of developing schizophrenia.
b. in family studies of schizophrenia, the genetic influence can be separated from the environmental impact.
c. if one person in a family has a particular subtype of schizophrenia, e.g., paranoid, the other family members inherit a predisposition for that subtype only.
d. the more severe a parent's schizophrenic disorder, the less likely the children are to develop it.
Question 2
The Genain quadruplets Nora, Iris, Myra and Hester showed us that
a. The course, symptoms and prognosis of schizophrenia can vary even among quadruplets raised in the same household
b. The course, symptoms and prognosis of schizophrenia can be determined by birth weight
c. Schizophrenia is almost entirely genetic in its etiology
d. Having the same family environment largely ensures the same outcome in schizophrenia
Some organisms used as models in genetic research
Miocene apes were found throughout Europe, continental Asia, and Africa.
Research Methods
Infant monkey is shown with cloth mother from Harlow’s studies.
Relative lifetime risk of schizophrenia
Selected Broad Sense Heritability (H2) Values from Human Twin Studies