Answer to Question 1
Answer: Many contemporary models of the etiology of mental disorders suggest that genetic factors or diatheses interact with environmental factors in complex ways to cause mental disorders. A person may have a genetic risk of developing schizophrenia, but may not develop the disorder in the absence of environmental stress. Such a situation exemplifies a gene-environment interaction. An example of gene-environment correlation would be if an individual inherited a predisposition to respond to stressful situations with anxiety and was raised in a way that encouraged or rewarded anxious behavior.
Answer to Question 2
Answer: Gender roles may cause problems (e.g., women are raised to show dependency and helplessness, which may cause depression). Gender roles may affect the expression of problems (e.g., it is socially acceptable for women to show depression, and for men to show physical illness). Gender roles can affect the consequences of problems (e.g., once a phobia develops, it is socially acceptable for women, but not men, to continue to avoid the feared object, and this avoidance may exacerbate the problem for women).
The colors of peppers are determined by the interaction of several genes
Phylogeny based on the FIT2 gene
The locations of disease-causing mutations in the cystic fibrosis gene
Gap gene expression patterns are activated by coordinate genes
Phenotype patterns in the F2 of a dihybrid cross that result from epistatic gene interaction
How gene drive alleles can spread through populations