Genetic and Environmental Foundations - Human Development

Vocabulary flashcards covering key genetic and environmental foundations of human development from Chapter 2.

Genotype

An individual's unique genetic information.

Phenotype

An individual's directly observable characteristics.

Chromosomes

Structures that store and transmit genetic information.

DNA

The substance of which genes and chromosomes are made.

Gene

A segment of DNA located along a chromosome.

Meiosis

A process that creates gametes (sex cells), halves the chromosome number, and promotes genetic variability.

Gametes

Sex cells, specifically sperm and ovum.

Zygote

The cell formed when sperm and ovum unite, having $46$ chromosomes.

Autosomes

The $22$ matching pairs of chromosomes in humans.

Sex Chromosomes

The $23\text{rd}$ pair of chromosomes (XX = female; XY = male in lecture terminology) that determine sex.

Fraternal (Dizygotic) Twins

Twins resulting from two zygotes (two fertilized ova).

Identical (Monozygotic) Twins

Twins resulting when one zygote divides into two individuals.

Alleles

Two forms of the same gene, with one inherited from each parent.

Homozygous

Having two alleles that are alike (AA or aa).

Heterozygous

Having two alleles that differ (Aa).

Dominant-Recessive Inheritance

A pattern of inheritance where the dominant allele affects characteristics when present, while a recessive allele can be passed on by a carrier without being expressed.

Genomic Imprinting

A genetic influence where a chemical marker activates one allele in a pair, which is often temporary and may not pass to the next generation.

Mutation

A sudden, permanent change in a DNA segment that may occur spontaneously or result from hazardous environmental agents.

Polygenic Inheritance

A pattern of inheritance in which many genes affect a characteristic, such as height, weight, intelligence, and personality.

Down Syndrome

A chromosomal abnormality resulting when the $21\text{st}$ chromosome pair fails to separate during meiosis.

Genetic Counseling

A service that helps couples assess hereditary-disorder risk and choose a course of action.

Direct Family Influence

A family context interaction involving a direct two-person relationship.

Indirect Family Influence

A family interaction where a third party affects a relationship, such as a healthy marriage fostering effective coparenting.

Socioeconomic Status (SES)

An index combining three related variables: years of education, occupational prestige/skill, and income.

Collectivism

A cultural value system that stresses group goals, interdependence, responsibility to others, social harmony, and collaboration.

Individualism

A cultural value system that emphasizes personal needs, independence, achievement, exploration, and choice.

Behavioral Genetics

A field of study that explores the contributions of nature and nurture to differences in human traits and abilities.

Heritability Estimates

Measures of the extent to which individual differences in complex traits are due to heredity, ranging from $0$ to $1.00$.

Kinship Studies

Studies that compare twins or adoptees and biological parents to estimate trait heritability.

Gene-Environment Interaction

The principle that people can respond differently to the same environment because of differences in genetic makeup.

Gene-Environment Correlation

The concept that genes can influence the environments to which people are exposed.

Passive Correlation

A type of gene-environment correlation where the environment is provided directly to the child.

Evocative Correlation

A type of gene-environment correlation where genetically influenced characteristics evoke reactions from others.

Active Correlation (Niche-Picking)

A type of gene-environment correlation where people actively select environments that fit their tendencies.

Epigenesis

Ongoing, bidirectional exchanges where genes affect behavior and experiences, and behavior and experiences affect gene expression.

Epigenetics

The study of how the environment alters gene expression, with methylation given as an example.