Ch. 4. 1. Genetics and Evolution of Behavior Flashcards
How does a sex-linked gene differ from a sex-limited gene?
A sex-linked gene is on the X or Y chromosome. A sex-limited gene is on an autosomal chromosome, but activated in one sex more than the other.
How does adding a methyl or acetyl group to a histone pro-
tein alter gene activity?
Adding a methyl group turns genes off. An acetyl group loosens histone’s grip and increases gene activation
How does an epigenetic change differ from a mutation
A mutation is a permanent change in part of a chro- mosome. An epigenetic change is an increase or decrease in the activity of a gene or group of genes.
What are the main types of evidence to estimate the heritabil- ity of some behavior?
One type of evidence is greater similarity between monozygotic twins than dizygotic twins.
Another is resemblance between adopted children and their biological parents.
A third is a demonstration that a particular gene is more common than average among people who show a particular behavior.
Suppose someone determines the heritability of IQ scores for a given population. Then society changes in a way that provides the best possible opportunity for everyone within that population. Will heritability of IQ increase, decrease, or stay the same?
Heritability will increase. Heritability estimates how much of the variation is due to differences in genes. If everyone has the same environment, then differences in environment cannot account for much of the remaining differences in IQ scores. Therefore, the relative role of genetic differences will be greater.
