Chapter 3: Biology of Behavior

Question 1

DNA

Answer 1

Genes:

• small segments of DNA
• influence specific characteristics by directing snyth of dif proteins

Alleles:

• pairs in which genes occur
• one from mom, one from dad
• dominant or recessive

Question 2

Behavioral Genetics

Answer 2

• looks at nature vs nurture differences in traits
• by studying twin adoptees, can disentangle contribution of heredity to behavior
• environment influences how and when genes affect behavior

Question 3

Polygenic Effects

Answer 3

• when a number of gene pairs combine their influences to create a single phenotypic trait
• skin color
• weight etc

Question 4

Monogenic

Answer 4

• passing of a trait based on a single gene
• i.e. huntington’s disease (one afflicted parent, 50/50 chance child gets it)
• dominant genes

Question 5

Heritability

Answer 5

• refers to a population, not an individual
• dependent on the environment
• proportion of observed phenotypic variants in a group that can be explained or accounted for by genetic variance
• statistic estimate of extent to which variation in a trait in a population is due to genetics
• even when heritability is high, phenotype of offspring and parental units are not identical

Question 6

Epigenetics

Answer 6

• how environment changes gene expression
• environmental events affect how and when genes are activated/deactivated
• does not change structure of DNA, just activity

Question 7

Codominance

Answer 7

• both alleles are expressed

- i.e. bloodtype