1-genestud Flashcards
twin study
Exploits two naturally occurring “accidents”in reproduction.
Exploits two naturally occurring “accidents”in reproduction.
twin study
Monozygotic Twins
Single fertilized egg divides and develops as two genetically identical siblings.
Single fertilized egg divides and develops as two genetically identical siblings.
Monozygotic Twins
Dizygotic Twins:
Two separate eggs released and fertilized. Two “normal” siblings (share 50% of genes) result.
Two separate eggs released and fertilized. Two “normal” siblings (share 50% of genes) result.
Dizygotic Twins:
What are the assumptions of twin studies if they are raised in the same household?
Co-twins raised together are exposed to much of the same life experiences, whether mono or di.
Then, if mono are more similar than di, must be due to greater genetic similarity.
Heritability Index (H^2)
(rmz – rdz) x 2.
Result is interpreted as proportion of trait variance attributable to shared genes.
Result is interpreted as proportion of trait variance attributable to shared genes.
Heritability Index (H^2)
What are the criticisms of twin studies?
Environments may be more similar for mono than di.
Parents often rate twins. May overemphasize similarities of mono and diffs between di.
What are the four misconceptions about heredity?
- If heritability of trait is high, society has little influence.(Opposite tends to be true)
- If a trait is inherited, it will have similar effects in the various people who inherit it. (No one-to-one relationship between what is inherited and form in which it is displayed.)
- If a trait is inherited, it is responsible for observed between-groups differences.(The effects of genes on some trait are limited to environmental contexts where they’re studied.)
- The effects of environment and heredity are entirely independent. (People with certain genes tend to create and choose certain environments.)
epigenetics
environmental control of genetic expression
***check textbook for definition
environmental control of genetic expression
***check textbook for definition
epigenetics
5-HTT
Short allele of 5-HTT gene associated with decreased serotonergic functioning.
short allele associated with greater concentrations of stress hormones only in response to stress
Short allele of certain gene associated with decreased serotonergic functioning.
short allele associated with greater concentrations of stress hormones only in response to stress
5-HTT