Genetics & Prenatal Development Vocabulary

Comprehensive vocabulary flashcards covering genetics, inheritance patterns, prenatal development stages, risk factors, and newborn assessments from Week 3 of PSY 240.

Autosomes

The 22 pairs of chromosomes in human cells that do not determine biological sex.

Sex Chromosomes

The single pair of chromosomes (X or Y) that determine an individual's biological sex.

Genes

Segments of DNA that code for a protein or trait.

Alleles

Different forms of a gene, which can be identical (homozygous) or different (heterozygous).

Homozygous

Having identical copies of a gene for a specific trait.

Heterozygous

Having different copies of a gene for a specific trait.

Genotype

The specific genetic makeup or genes that an individual possesses.

Phenotype

The observable physical or behavioral traits of an individual.

Dominant/Recessive Inheritance

A pattern of inheritance controlled by one gene, where a dominant gene masks a recessive gene (e.g., hair type, eye color).

X-linked Inheritance

A pattern of inheritance where traits are determined by genes on the X chromosome, making males more likely to be affected because they have only 1 X chromosome (e.g., color vision deficiency).

Polygenic Inheritance

A pattern of inheritance where many genes determine a single phenotype (e.g., skin color).

Epigenetic (Multifactorial) Inheritance

A pattern of inheritance involving the interaction between genes and the environment (e.g., personality, cancer).

Reaction Range

The potential variation in a trait (e.g., intelligence) determined by genetics, where the realized quality depends on the environment.

Passive Genotype-Environment Correlation

A correlation occurring when family members provide an environment that fosters a trait matching the child's genetic disposition.

Evocative (or Reactive) Genotype-Environment Correlation

A correlation occurring when a child's inherited traits evoke specific responses from others in their environment.

Active (or Niche-Picking) Genotype-Environment Correlation

A correlation occurring when children choose environments that suit their genetic traits.

Recessive Disorders

Genetic conditions caused by two recessive copies of a gene (e.g., sickle cell disease, cystic fibrosis).

Autosomal Dominant Disorders

Genetic conditions caused by a gene inherited from one parent (e.g., Huntington's disease, achrondoplasia).

Sex-Linked Disorders

Genetic conditions caused by a gene on the X chromosome, which are more common in males (e.g., hemophilia, Duchenne muscular dystrophy).

Chromosomal Abnormalities

Conditions caused by having too many or too few chromosomes (e.g., Down syndrome [trisomy 21], Turner syndrome [XO], Klinefelter syndrome [XXY]).

Fertilization

The process where an ovum containing 23 single chromosomes accepts a sperm containing 23 single chromosomes in the fallopian tube.

Zygote

The single cell formed when an ovum and sperm combine to create 23 pairs of chromosomes.

Monozygotic (MZ) Twins

Identical twins developed from one egg and one sperm that share 100% of their genes.

Dizygotic (DZ) Twins

Fraternal twins developed from two separate eggs and two separate sperm that share 50% of their genes.

Infertility

The inability to become pregnant, or maintain a pregnancy, after 12 months of regular, unprotected sex during ovulation (or 6 months if age 35+).

Stages of Prenatal Development

The three sequential stages of prenatal growth: Germinal (Zygotic), Embryonic, and Fetal.

Germinal (Zygotic) Stage

The first stage of prenatal development, lasting from conception to 2 weeks.

Embryonic Stage

The second stage of prenatal development, lasting from 2 to 8 weeks, characterized by rapid development of the placenta and major body systems.

Fetal Stage

The final stage of prenatal development, lasting from 8 weeks to birth, characterized by complex organ development, rapid brain growth, and appearance of bone.

Age of Viability

The age at which a fetus has a chance of surviving outside the womb, approximately 24 weeks.

Genetic Mutations

Sudden, permanent changes in DNA.

Teratogens

Environmental factors or substances that can harm an embryo or fetus, especially during critical periods when body systems are forming.

Premature Birth

Birth that occurs before the 38th week of gestation.

Low Birth Weight

A newborn weight of less than 5.5 lbs.

Apgar Scale

A newborn assessment evaluating five physical measures (Appearance, Pulse, Grimace, Activity, Respiration) scored 0 to 2 shortly after birth.