Genetic and Chromosomal Abnormalities & Nature and Nurture

Flashcards defining key vocabulary terms related to genetic inheritance, chromosomal disorders, genetic testing, and methods in behavioral genetics.

Mutations

Permanent alterations in genes or chromosomes.

Autosomes

The 22 pairs of chromosomes not related to sexual expression.

Sex Chromosomes

The pair of chromosomes that determines sex (XX for female, XY for male).

Dominant Inheritance of Defects

A pattern of inheritance where one affected parent with one abnormal dominant gene and one normal recessive gene can pass it on (e.g., achondroplasia, Huntington's disease).

Recessive Inheritance of Defects

A pattern of inheritance that requires two copies of the recessive gene, one from each parent (e.g., cystic fibrosis, sickle-cell anemia).

Incomplete Dominance

A pattern of inheritance where a trait is partially expressed when two different alleles are present (e.g., sickle-cell trait).

Sex-Linked Inheritance

Disorders carried on the X chromosome that affect males and females differently because males have only one X chromosome (e.g., red-green color blindness, hemophilia, Duchenne muscular dystrophy).

Chromosomal Abnormalities

Conditions occurring due to errors in cell division, resulting in an extra or missing chromosome.

Klinefelter Syndrome (XXY)

A chromosomal abnormality in males resulting in some female secondary sex characteristics and sterility.

Turner Syndrome (XO)

A chromosomal abnormality in females characterized by short stature and infertility.

Down Syndrome (Trisomy 21)

A chromosomal abnormality caused by an extra 21st chromosome, resulting in moderate-to-severe intellectual disability and characteristic physical features.

Genetic Counseling

A service that advises prospective parents about their risk of having children with hereditary defects.

Genetic Testing

The analysis of chromosomes and genes to identify potential defects or predispositions.

Behavioral Genetics

The quantitative study of the relative influence of heredity and environment on behavior.

Heritability

A statistical estimate of how much of the variation in a trait within a population is due to genetic factors, expressed as a percentage ($0.0$ to $1.0$).

Concordant

The tendency for individuals (especially twins) to share the same trait or disorder.

Family Studies

A method of studying heredity and environment that compares traits among relatives with known genetic relationships.

Twin Studies

A method of studying heredity and environment that compares concordance rates between monozygotic (identical) and dizygotic (fraternal) twins.

Adoption Studies

A method of studying heredity and environment that compares adopted children's traits to those of their biological and adoptive parents.