Nature V. Nurture

Unit 1 - Chapter 2

Our Genetic Makeup

Most cells contain the same 23 pairs of chromosomes - 22 pairs of autosomes, 1 pair of sex chromosomes. * EXCEPTION: gametes, the same sex cells

Chromosomes are comprised of ____, the double helix made up of ________

genes , deoxyribonucleic acid (DNA)

-genes code for proteins and proteins determine traits

Two process for cell reproduction

Mitosis - make a copy

Meiosis - specific to gametes

How alike are we?

we share 99.7-99.9% of our genetic code with all other humans

Twins - Dizygotic (fraternal) and Monoaygotic (identical)

How do genes contribute to difference?

Inheritance and Polygenic inheritance - genetic and chromosomal disorders and abnormalities

Alleles

variations in the form of genes

matching alleles - homozygous (trait is expressed)

mismatching alleles - heterzygous

dominant (recessive inheritance) and incomplete dominance (a blend)

Behavioral Genetics

Genotype - the genetic makeup of an individual that influences behavior and traits

Phenotype - the observable characteristics or traits of an individual resulting from the interaction of genotype with the environment

Canalization

some genes set strict biological programs

Gene-enviro correlations

genes and environments can be complementary

3 types - passive, reactive/evocative, and active/selective

Passive gene correlations

parents provide the genes, parents provide the growing environment

example - a child inherits musical talent from their parents and is raised in a home filled with music

common early in life

Reactive/evocative gene correlation

genetical predisposition gives rise to traits that evoke reactions from environment that further shape that trait

example - a shy child may receive encouragement to socialize, reinforcing their social skills

present throughout life

Active/selective gene correlation

genetic predispositions set us up to seek complementary environments (niche picking)

example - an athletic child may choose to join sports teams, enhancing their physical abilities

Gene X Environment Interactions

genes may make us susceptible to environment

Epigenetics

“above the gene” - environment may (de)activate certain genes (epigenome)