Exam 1: Biology and Behavior Flashcards
Minnesota Twin Study
Bouchard
Identical twins reared apart
-100 pairs of twins
-Gerald Levey and Mark Newman were identical twins separated at birth
-The twins showed similaries, both physical and behavioral (work history)
Identified genetic contributions to “almost every behavioral trait so far investigated from reaction time to religiosity)
Reproductive germ cell contains ___ chromosomes divides and produces either sperm cell or ova which contains half the parent cell’s original chromosomes (__)
46; 23
Allele
Each of two forms of a gene located at the same place on corresponding pairs of chromosomes.
Homozygous- identical alleles
Heterozygous-different alleles
X-linked Inheritance and example
Harmful allele is carried on X chromosome.
People with XY are more likely to be affected than XX combo.
Red-Green Color Blindness: have 25% of having child with colorblindness. 50% chance of having son with color blindness. 0% chance of having daughter with color blindness.
What kind of gene-pair inheritance is complex and rare?
Single gene-pair inheritance
Polygenic inheritance and example
Characteristics influences by multiple pairs of genes.
Eye color
5 fundamental relationships between genotype, environment, and phenotype
- Parent’s genetic contribution to children’s genotype
- The contribution of children’s genotype to their own phenotype
- Contribution of children’s environments to their phenotypes
- Childrens phenotypes on their environments
- Children’s environments on genotypes
Parent genotype -> child genotype
each parent gives 23 genes to child
Differences between parent and child genotype are due to
-random assortment
-crossing over: dna swap
-mutation
Child genotype -child phenotype
What is endophenotypes?
Explain gene expression & developmental changes
Explain gene expression & dominance patterns
Phenotypes are physical and behavioral traits.
Endophenotypes: intermediate phenotypes that mediate the path between genes and behavior.
Gene expression: some genes on, some off. Regulator genes control activity of other genes. Ex: thalidomide
Dominance patterns based on alleles and polygenetic inheritance. IQ
Endophenotypes
unobservable, intermediate aspects of phenotype that impact behavior.
Brain and nervous systems
Mediate path between genes and behavior
Example of a phenotype produced by a genotype-environment interaction
Phenylketonuria (PKU)- disorder released to defective recessive gene on chromosome 12
No diet and eat phenylalanine (amino acid) -> impaired brain development and intellectual disabilities
Diet -> normal and intellectual disabilities are avoided
Study: the effects of abusive parenting interact with child’s genotype to produce different adult outcome
Find out why: maltreated children become violet and antisocial adults whereas others with abuse don’t
MAOA gene: inhibits neurotransmitters associated with aggression
Inactive MAOA: 85% formed antisocial behavior and 10 times more likely to convict of violent crime
Active: less effects
How do parents contribute to child’s environment
Their genotypes form their phenotypes and these behaviors and qualities create the environment for their children.
Children’s educational outcomes are predicted by parental alleles that child did not inherit.
“genetic nurture”
Childs phenotype-childs environment
outgoing baby is going to create an environment filled with people.
Children create their own environments by actively selecting surroundings and experiences that match their interests and personalities.
Heritability
-applies only to populations living in a particular environment
