Chapter 2 - Heredity and Environment

Nature vs. nurture

• nature = genetics

• nurture = environmental influences

Each cell has ____ chromosome pairs

23

Autosomes

the first 22 pairs of chromosomes

Sex chromosome

23rd pair of chromosomes that determines the sex of the baby

Sex cells have ___ chromosomes and the rest have ____

23, 46

Certain traits don’t get expressed in offspring as a result of ____

Dominant and recessive genes

Dominant gene

Causes a trait to be expressed as the phenotype

Recessive gene

Trait that’s only expressed if the offspring receives 2 copies of it

Monozygotic twins

fertilized egg divides in half before meiosis

Dizygotic twins

2 fertilized eggs in the womb

Congenital anomalies

birth defects

Recessive disorder

Disorder carried on the recessive gene - people can be carriers and not actually have the disease

Genetic counseling

Healthcare service used by parents to determine the likelihood that their child will have a genetic disorder

Down syndrome

a child is born with an extra pair of chromosome 21

Who is at a higher risk for Down syndrome?

older mothers

Down syndrome risks

health + intellectual

Sex-linked/X linked disorder

disorder carried on the X chromosome

Sex linked disorders are more common in

Boys because they have XY chromosomes

classical conditioning

automatic involuntary response is associated with a stimulus that doesn’t usually produce a strong response

operant conditioning

behavior producing a positive consequence is likely to be repeated

reinforcement

consequences of operant conditioning feel good

punishment

consequences of operant conditioning feel bad

social learning

learning through watching other people and watching the consequences other people experience

normative events

points in life that happen to most people + a lot of time are a big deal (ex: graduation, getting married, having kids, buying a house)

non-normative events

life events that don’t happen to everyone (ex: illness, housefires, immigration, etc)